diff --git a/includes/common.inc b/includes/common.inc
index c3d38ef57784c75e3c54d8621071ac4ee6aba3dc..9ef8ce9dcd539b7c0ac67f1da876ab371c174285 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -2642,27 +2642,26 @@ function drupal_add_html_head_link($attributes, $header = FALSE) {
  * Calling drupal_static_reset('drupal_add_css') will clear all cascading
  * stylesheets added so far.
  *
- * If preprocessing is turned on, the cascading style sheets added using this
- * function will be preprocessed before they are added to the HTML header of the
- * page. Preprocessing merges all the CSS files into one file, which is then
- * compressed by removing all extraneous white space. Note that preprocessed
- * inline stylesheets will not be aggregated into this single file; instead,
- * they will just be compressed when being output on the page. External
- * stylesheets will also not be aggregated.
- *
- * The reason for merging the CSS files is outlined quite thoroughly here:
+ * If CSS aggregation/compression is enabled, all cascading style sheets added
+ * with $options['preprocess'] set to TRUE will be merged into one aggregate
+ * file and compressed by removing all extraneous white space.
+ * Preprocessed inline stylesheets will not be aggregated into this single file;
+ * instead, they are just compressed upon output on the page. Externally hosted
+ * stylesheets are never aggregated or compressed.
+ *
+ * The reason for aggregating the files is outlined quite thoroughly here:
  * http://www.die.net/musings/page_load_time/ "Load fewer external objects. Due
  * to request overhead, one bigger file just loads faster than two smaller ones
  * half its size."
  *
- * However, you should *not* preprocess every file as this can lead to redundant
- * caches. You should set $options['preprocess'] to FALSE when your styles are
- * only used on a few pages of the site. This could be a special admin page, the
- * homepage, or a handful of pages that does not represent the majority of the
- * pages on your site.
+ * $options['preprocess'] should be only set to TRUE when a file is required for
+ * all typical visitors and most pages of a site. It is critical that all
+ * preprocessed files are added unconditionally on every page, even if the
+ * files do not happen to be needed on a page. This is normally done by calling
+ * drupal_add_css() in a hook_init() implementation.
  *
- * Typical candidates for preprocessing are for example styles for nodes across
- * the site, or styles used in the theme.
+ * Non-preprocessed files should only be added to the page when they are
+ * actually needed.
  *
  * @param $data
  *   (optional) The stylesheet data to be added, depending on what is passed
@@ -2710,9 +2709,8 @@ function drupal_add_html_head_link($attributes, $header = FALSE) {
  *     always come last.
  *   - 'media': The media type for the stylesheet, e.g., all, print, screen.
  *     Defaults to 'all'.
- *   - 'preprocess': If TRUE, Allows the CSS to be aggregated and compressed if
- *     the Optimize CSS feature has been turned on under the performance
- *     section.  Defaults to TRUE.
+ *   - 'preprocess': If TRUE and CSS aggregation/compression is enabled, the
+ *     styles will be aggregated and compressed. Defaults to FALSE.
  *   - 'browsers': An array containing information specifying which browsers
  *     should load the CSS item. See drupal_pre_render_conditional_comments()
  *     for details.
@@ -2740,7 +2738,7 @@ function drupal_add_css($data = NULL, $options = NULL) {
       'type' => 'file',
       'weight' => CSS_DEFAULT,
       'media' => 'all',
-      'preprocess' => TRUE,
+      'preprocess' => FALSE,
       'data' => $data,
       'browsers' => array(),
     );
@@ -3576,6 +3574,25 @@ function drupal_region_class($region) {
  * Calling drupal_static_reset('drupal_add_js') will clear all JavaScript added
  * so far.
  *
+ * If JavaScript aggregation is enabled, all JavaScript files added with
+ * $options['preprocess'] set to TRUE will be merged into one aggregate file.
+ * Preprocessed inline JavaScript will not be aggregated into this single file.
+ * Externally hosted JavaScripts are never aggregated.
+ *
+ * The reason for aggregating the files is outlined quite thoroughly here:
+ * http://www.die.net/musings/page_load_time/ "Load fewer external objects. Due
+ * to request overhead, one bigger file just loads faster than two smaller ones
+ * half its size."
+ *
+ * $options['preprocess'] should be only set to TRUE when a file is required for
+ * all typical visitors and most pages of a site. It is critical that all
+ * preprocessed files are added unconditionally on every page, even if the
+ * files are not needed on a page. This is normally done by calling
+ * drupal_add_css() in a hook_init() implementation.
+ *
+ * Non-preprocessed files should only be added to the page when they are
+ * actually needed.
+ *
  * @param $data
  *   (optional) If given, the value depends on the $options parameter:
  *   - 'file': Path to the file relative to base_path().
@@ -3617,9 +3634,8 @@ function drupal_region_class($region) {
  *   - cache: If set to FALSE, the JavaScript file is loaded anew on every page
  *     call; in other words, it is not cached. Used only when 'type' references
  *     a JavaScript file. Defaults to TRUE.
- *   - preprocess: Aggregate the JavaScript if the JavaScript optimization
- *     setting has been toggled in admin/config/development/performance. Note
- *     that JavaScript of type 'external' is not aggregated. Defaults to TRUE.
+ *   - preprocess: If TRUE and JavaScript aggregation is enabled, the script
+ *     file will be aggregated. Defaults to FALSE.
  *
  * @return
  *   The current array of JavaScript files, settings, and in-line code,
@@ -3712,7 +3728,7 @@ function drupal_js_defaults($data = NULL) {
     'scope' => 'header',
     'cache' => TRUE,
     'defer' => FALSE,
-    'preprocess' => TRUE,
+    'preprocess' => FALSE,
     'version' => NULL,
     'data' => $data,
   );
diff --git a/includes/locale.inc b/includes/locale.inc
index 6437c245da91ea345696e1f80b398cd6ee0625b7..50f4429077f1bedea0dbfe406b5e07a7010bb251 100644
--- a/includes/locale.inc
+++ b/includes/locale.inc
@@ -1775,7 +1775,7 @@ function _locale_rebuild_js($langcode = NULL) {
  */
 function _locale_translate_language_list($translation, $limit_language) {
   // Add CSS.
-  drupal_add_css(drupal_get_path('module', 'locale') . '/locale.css', array('preprocess' => FALSE));
+  drupal_add_css(drupal_get_path('module', 'locale') . '/locale.css');
 
   $languages = language_list();
   unset($languages['en']);
diff --git a/includes/theme.inc b/includes/theme.inc
index 93895c8f8b479216bd4e1b51cc5a824a5a1f66de..5d87379438495f69c8e995f94eef76480a3f738c 100644
--- a/includes/theme.inc
+++ b/includes/theme.inc
@@ -164,7 +164,7 @@ function _drupal_theme_initialize($theme, $base_theme = array(), $registry_callb
   // And now add the stylesheets properly
   foreach ($final_stylesheets as $media => $stylesheets) {
     foreach ($stylesheets as $stylesheet) {
-      drupal_add_css($stylesheet, array('weight' => CSS_THEME, 'media' => $media));
+      drupal_add_css($stylesheet, array('weight' => CSS_THEME, 'media' => $media, 'preprocess' => TRUE));
     }
   }
 
@@ -189,7 +189,7 @@ function _drupal_theme_initialize($theme, $base_theme = array(), $registry_callb
 
   // Add scripts used by this theme.
   foreach ($final_scripts as $script) {
-    drupal_add_js($script, array('weight' => JS_THEME));
+    drupal_add_js($script, array('weight' => JS_THEME, 'preprocess' => TRUE));
   }
 
   $theme_engine = NULL;
diff --git a/modules/aggregator/aggregator.module b/modules/aggregator/aggregator.module
index 172361a2b8ae7f109476d044efaf452ea9e06729..a5ff986d7adc73ce298f5960ee91f271f4a92f24 100644
--- a/modules/aggregator/aggregator.module
+++ b/modules/aggregator/aggregator.module
@@ -286,7 +286,7 @@ function _aggregator_category_title($category) {
  * Implements hook_init().
  */
 function aggregator_init() {
-  drupal_add_css(drupal_get_path('module', 'aggregator') . '/aggregator.css');
+  drupal_add_css(drupal_get_path('module', 'aggregator') . '/aggregator.css', array('preprocess' => TRUE));
 }
 
 /**
diff --git a/modules/block/block.admin.inc b/modules/block/block.admin.inc
index 4d197e1e7410f132fcf7e85b5e47828cff276176..8d973832639ed08ce7752989c1ede0585faaa0f1 100644
--- a/modules/block/block.admin.inc
+++ b/modules/block/block.admin.inc
@@ -10,7 +10,7 @@
  * Menu callback for admin/structure/block/demo.
  */
 function block_admin_demo($theme = NULL) {
-  drupal_add_css(drupal_get_path('module', 'block') . '/block.css', array('preprocess' => FALSE));
+  drupal_add_css(drupal_get_path('module', 'block') . '/block.css');
   return '';
 }
 
@@ -53,7 +53,7 @@ function block_admin_display($theme = NULL) {
  */
 function block_admin_display_form($form, &$form_state, $blocks, $theme) {
 
-  drupal_add_css(drupal_get_path('module', 'block') . '/block.css', array('preprocess' => FALSE));
+  drupal_add_css(drupal_get_path('module', 'block') . '/block.css');
 
   $block_regions = system_region_list($theme, REGIONS_VISIBLE) + array(BLOCK_REGION_NONE => '<' . t('none') . '>');
 
diff --git a/modules/book/book.module b/modules/book/book.module
index 7651a7aa67be01acfcfe5d095553903d5c6dc8a8..8ef55f4f122003fdfe60dd2f456b01670026469c 100644
--- a/modules/book/book.module
+++ b/modules/book/book.module
@@ -222,7 +222,7 @@ function book_admin_paths() {
  * Implements hook_init().
  */
 function book_init() {
-  drupal_add_css(drupal_get_path('module', 'book') . '/book.css');
+  drupal_add_css(drupal_get_path('module', 'book') . '/book.css', array('preprocess' => TRUE));
 }
 
 /**
diff --git a/modules/color/color.module b/modules/color/color.module
index 682518f048bfc4bee7d4f27243a4916576ec565f..6a3ca99c4c6fc2edbca8f216499daec60a67adb2 100644
--- a/modules/color/color.module
+++ b/modules/color/color.module
@@ -189,7 +189,7 @@ function color_scheme_form($complete_form, &$form_state, $theme) {
       ),
       // Add custom CSS.
       'css' => array(
-        $base . '/color.css' => array('preprocess' => FALSE),
+        $base . '/color.css' => array(),
       ),
       // Add custom JavaScript.
       'js' => array(
diff --git a/modules/comment/comment.module b/modules/comment/comment.module
index c6b2a91556d0e5c73f97909f6d22f70f80bbe0a0..62e2d3d4ab98f4ec71949db76ee9b9d40c600a28 100644
--- a/modules/comment/comment.module
+++ b/modules/comment/comment.module
@@ -289,6 +289,13 @@ function comment_menu() {
   return $items;
 }
 
+/**
+ * Implements hook_init().
+ */
+function comment_init() {
+  drupal_add_css(drupal_get_path('module', 'comment') . '/comment.css', array('preprocess' => TRUE));
+}
+
 /**
  * Implements hook_menu_alter().
  */
@@ -716,7 +723,6 @@ function comment_node_page_additions($node) {
       $comments = comment_load_multiple($cids);
       comment_prepare_thread($comments);
       $build = comment_view_multiple($comments, $node);
-      $build['#attached']['css'][] = drupal_get_path('module', 'comment') . '/comment.css';
       $build['pager']['#theme'] = 'pager';
       $additions['comments'] = $build;
     }
diff --git a/modules/dblog/dblog.module b/modules/dblog/dblog.module
index 7e59501ed31ee432fef33b9046b3deb0bb5f03a8..32ab03f767e6697493a5d61518865f19bdf385e5 100644
--- a/modules/dblog/dblog.module
+++ b/modules/dblog/dblog.module
@@ -91,7 +91,7 @@ function dblog_menu() {
 function dblog_init() {
   if (arg(0) == 'admin' && arg(1) == 'reports') {
     // Add the CSS for this module
-    drupal_add_css(drupal_get_path('module', 'dblog') . '/dblog.css', array('preprocess' => FALSE));
+    drupal_add_css(drupal_get_path('module', 'dblog') . '/dblog.css');
   }
 }
 
diff --git a/modules/field/field.attach.inc b/modules/field/field.attach.inc
index 3753b2f75634da6eac54d9d3af8ecbcc91b3bdd0..3383a5793b37c86fedb2ea725af9ec6eed5c3dd4 100644
--- a/modules/field/field.attach.inc
+++ b/modules/field/field.attach.inc
@@ -542,7 +542,6 @@ function field_attach_form($entity_type, $entity, &$form, &$form_state, $langcod
 
   // Add custom weight handling.
   list($id, $vid, $bundle) = entity_extract_ids($entity_type, $entity);
-  $form['#attached']['css'][] = drupal_get_path('module', 'field') . '/theme/field.css';
   $form['#pre_render'][] = '_field_extra_fields_pre_render';
   $form['#entity_type'] = $entity_type;
   $form['#bundle'] = $bundle;
@@ -1129,9 +1128,6 @@ function field_attach_view($entity_type, $entity, $view_mode, $langcode = NULL)
   $output['#entity_type'] = $entity_type;
   $output['#bundle'] = $bundle;
 
-  // Include CSS styles.
-  $output['#attached']['css'][] = drupal_get_path('module', 'field') . '/theme/field.css';
-
   // Let other modules alter the renderable array.
   $context = array(
     'entity_type' => $entity_type,
diff --git a/modules/field/field.module b/modules/field/field.module
index e421d9742da29ae6b14eaea9e62ef1be17bee38b..a429499f79a1e44589157dd13e33985e59a8c218 100644
--- a/modules/field/field.module
+++ b/modules/field/field.module
@@ -165,6 +165,13 @@ function field_theme() {
   );
 }
 
+/**
+ * Implements hook_init().
+ */
+function field_init() {
+  drupal_add_css(drupal_get_path('module', 'field') . '/theme/field.css', array('preprocess' => TRUE));
+}
+
 /**
  * Implements hook_cron().
  *
@@ -811,7 +818,6 @@ function field_view_field($entity_type, $entity, $field_name, $display = array()
 
     if (isset($result[$field_name])) {
       $output = $result[$field_name];
-      $output['#attached']['css'][] = drupal_get_path('module', 'field') . '/theme/field.css';
     }
   }
 
diff --git a/modules/forum/forum.module b/modules/forum/forum.module
index 3258b3930bdb78c43d49ee57181b0e218c9a5900..a3d5e1c2174f78b7f4f7295ee5551f653c8d2592 100644
--- a/modules/forum/forum.module
+++ b/modules/forum/forum.module
@@ -221,7 +221,7 @@ function forum_menu_local_tasks_alter(&$data, $router_item, $root_path) {
  * Implements hook_init().
  */
 function forum_init() {
-  drupal_add_css(drupal_get_path('module', 'forum') . '/forum.css');
+  drupal_add_css(drupal_get_path('module', 'forum') . '/forum.css', array('preprocess' => TRUE));
 }
 
 /**
diff --git a/modules/help/help.admin.inc b/modules/help/help.admin.inc
index c05d854f41272c27a9ae12ef74ddf7bbb6d7817c..568a5ad2f532d79b26a837ff6df9008d1b7fb121 100644
--- a/modules/help/help.admin.inc
+++ b/modules/help/help.admin.inc
@@ -11,7 +11,7 @@
  */
 function help_main() {
   // Add CSS
-  drupal_add_css(drupal_get_path('module', 'help') . '/help.css', array('preprocess' => FALSE));
+  drupal_add_css(drupal_get_path('module', 'help') . '/help.css');
   $output = '<h2>' . t('Help topics') . '</h2><p>' . t('Help is available on the following items:') . '</p>' . help_links_as_list();
   return $output;
 }
diff --git a/modules/image/image.admin.inc b/modules/image/image.admin.inc
index cd822972ea18a35c2a2554ca33de20e646de777f..ce1b039b6af4bbe47cf1da110a2de091ea035ad7 100644
--- a/modules/image/image.admin.inc
+++ b/modules/image/image.admin.inc
@@ -16,7 +16,7 @@ function image_style_list() {
   $page['image_style_list'] = array(
     '#markup' => theme('image_style_list', array('styles' => $styles)),
     '#attached' => array(
-      'css' => array(drupal_get_path('module', 'image') . '/image.admin.css' => array('preprocess' => FALSE)),
+      'css' => array(drupal_get_path('module', 'image') . '/image.admin.css' => array()),
     ),
   );
 
@@ -48,7 +48,7 @@ function image_style_form($form, &$form_state, $style) {
 
   $form_state['image_style'] = $style;
   $form['#tree'] = TRUE;
-  $form['#attached']['css'][drupal_get_path('module', 'image') . '/image.admin.css'] = array('preprocess' => FALSE);
+  $form['#attached']['css'][drupal_get_path('module', 'image') . '/image.admin.css'] = array();
 
   // Show the thumbnail preview.
   $form['preview'] = array(
@@ -383,7 +383,7 @@ function image_effect_form($form, &$form_state, $style, $effect) {
   }
 
   $form['#tree'] = TRUE;
-  $form['#attached']['css'][drupal_get_path('module', 'image') . '/image.admin.css'] = array('preprocess' => FALSE);
+  $form['#attached']['css'][drupal_get_path('module', 'image') . '/image.admin.css'] = array();
   if (function_exists($effect['form callback'])) {
     $form['data'] = call_user_func($effect['form callback'], $effect['data']);
   }
diff --git a/modules/locale/locale.admin.inc b/modules/locale/locale.admin.inc
index 1235f8966a8d07afbaece684e69bb8a9659021fb..6ca3df30b035e616b7b572d53016d4af7edba845 100644
--- a/modules/locale/locale.admin.inc
+++ b/modules/locale/locale.admin.inc
@@ -784,7 +784,7 @@ function locale_translate_overview_screen() {
  */
 function locale_translate_seek_screen() {
   // Add CSS.
-  drupal_add_css(drupal_get_path('module', 'locale') . '/locale.css', array('preprocess' => FALSE));
+  drupal_add_css(drupal_get_path('module', 'locale') . '/locale.css');
 
   $elements = drupal_get_form('locale_translation_filter_form');
   $output = drupal_render($elements);
diff --git a/modules/node/node.module b/modules/node/node.module
index 5e875f281eac0191d4d2d52cc5359c536c09c117..0161ca1ba47b219786bbbf3afe780c2282518567 100644
--- a/modules/node/node.module
+++ b/modules/node/node.module
@@ -1998,7 +1998,7 @@ function _node_custom_theme() {
  * Implements hook_init().
  */
 function node_init() {
-  drupal_add_css(drupal_get_path('module', 'node') . '/node.css');
+  drupal_add_css(drupal_get_path('module', 'node') . '/node.css', array('preprocess' => TRUE));
 }
 
 function node_last_changed($nid) {
diff --git a/modules/poll/poll.module b/modules/poll/poll.module
index ee292aafa546db2b702b6fb7a8cf631071b68367..3d38f46b01fd9e3310a8701285f9f423a5db7f3a 100644
--- a/modules/poll/poll.module
+++ b/modules/poll/poll.module
@@ -31,7 +31,7 @@ function poll_help($path, $arg) {
  * Implements hook_init().
  */
 function poll_init() {
-  drupal_add_css(drupal_get_path('module', 'poll') . '/poll.css');
+  drupal_add_css(drupal_get_path('module', 'poll') . '/poll.css', array('preprocess' => TRUE));
 }
 
 /**
diff --git a/modules/search/search.module b/modules/search/search.module
index 2ab3a4210d27fe22361ce4449475649289a9d9a3..2138562a6e1bf23c8226f55053182b6e24d44b3a 100644
--- a/modules/search/search.module
+++ b/modules/search/search.module
@@ -97,6 +97,13 @@ function search_help($path, $arg) {
   }
 }
 
+/**
+ * Implements hook_init().
+ */
+function search_init() {
+  drupal_add_css(drupal_get_path('module', 'search') . '/search.css', array('preprocess' => TRUE));
+}
+
 /**
  * Implements hook_theme().
  */
@@ -875,9 +882,6 @@ function search_get_keys() {
  *   An HTML string containing the search form.
  */
 function search_form($form, &$form_state, $action = '', $keys = '', $type = NULL, $prompt = NULL) {
-  // Add CSS
-  drupal_add_css(drupal_get_path('module', 'search') . '/search.css', array('preprocess' => FALSE));
-
   if (!$action) {
     $action = 'search/' . $type;
   }
diff --git a/modules/simpletest/tests/ajax.test b/modules/simpletest/tests/ajax.test
index 97cd2f5d2ff3751e5d66e4e51abea0cd831e45f9..91572bda0d921c08dfc5b529589be160bda76d7f 100644
--- a/modules/simpletest/tests/ajax.test
+++ b/modules/simpletest/tests/ajax.test
@@ -53,7 +53,7 @@ class AJAXFrameworkTestCase extends AJAXTestCase {
    * Test behavior of ajax_render_error().
    */
   function testAJAXRenderError() {
-    $result = $this->drupalGetAJAX('ajax-test/render-error');
+    $result = $this->discardSettings($this->drupalGetAJAX('ajax-test/render-error'));
     // Verify default error message.
     $this->assertEqual($result[0]['command'], 'alert', t('ajax_render_error() invokes alert command.'));
     $this->assertEqual($result[0]['text'], t('An error occurred while handling the request: The server received invalid input.'), t('Default error message is output.'));
@@ -61,7 +61,7 @@ class AJAXFrameworkTestCase extends AJAXTestCase {
     $edit = array(
       'message' => 'Custom error message.',
     );
-    $result = $this->drupalGetAJAX('ajax-test/render-error', array('query' => $edit));
+    $result = $this->discardSettings($this->drupalGetAJAX('ajax-test/render-error', array('query' => $edit)));
     $this->assertEqual($result[0]['text'], $edit['message'], t('Custom error message is output.'));
   }
 }
diff --git a/modules/simpletest/tests/common.test b/modules/simpletest/tests/common.test
index 01635a5ea6dede878c4cd08981cce781ceb6c337..35c5bbc3b568542fda2a34b2fcd3136f8bea2948 100644
--- a/modules/simpletest/tests/common.test
+++ b/modules/simpletest/tests/common.test
@@ -621,7 +621,7 @@ class CascadingStylesheetsTestCase extends DrupalWebTestCase {
   function testRenderInlinePreprocess() {
     $css = 'body { padding: 0px; }';
     $css_preprocessed = '<style type="text/css" media="all">' . drupal_load_stylesheet_content($css, TRUE) . '</style>';
-    drupal_add_css($css, 'inline');
+    drupal_add_css($css, array('type' => 'inline', 'preprocess' => TRUE));
     $styles = drupal_get_css();
     $this->assertEqual(trim($styles), $css_preprocessed, t('Rendering preprocessed inline CSS adds it to the page.'));
   }
@@ -631,7 +631,7 @@ class CascadingStylesheetsTestCase extends DrupalWebTestCase {
    */
   function testRenderInlineNoPreprocess() {
     $css = 'body { padding: 0px; }';
-    drupal_add_css($css, array('type' => 'inline', 'preprocess' => FALSE));
+    drupal_add_css($css, array('type' => 'inline'));
     $styles = drupal_get_css();
     $this->assertTrue(strpos($styles, $css) > 0, t('Rendering non-preprocessed inline CSS adds it to the page.'));
   }
@@ -641,7 +641,7 @@ class CascadingStylesheetsTestCase extends DrupalWebTestCase {
    */
   function testRenderInlineFullPage() {
     $css = 'body { font-size: 254px; }';
-    $expected = 'font-size:254px;';
+    $expected = $css;
 
     // Create a node, using the PHP filter that tests drupal_add_css().
     $php_format_id = db_query_range('SELECT format FROM {filter_format} WHERE name = :name', 0, 1, array(':name' => 'PHP code'))->fetchField();
diff --git a/modules/system/system.module b/modules/system/system.module
index 05eb786617b7e4a33ae902681255d864e1cfa089..45144a245cb427de90cdf6b64b859acf4a4ed958 100644
--- a/modules/system/system.module
+++ b/modules/system/system.module
@@ -1066,6 +1066,7 @@ function system_library() {
     'js' => array(
       'misc/jquery.js' => array('weight' => JS_LIBRARY - 20),
     ),
+    'preprocess' => TRUE,
   );
 
   // jQuery Once.
@@ -1076,6 +1077,7 @@ function system_library() {
     'js' => array(
       'misc/jquery.once.js' => array('weight' => JS_LIBRARY - 19),
     ),
+    'preprocess' => TRUE,
   );
 
   // jQuery Form Plugin.
@@ -1120,7 +1122,7 @@ function system_library() {
       'misc/farbtastic/farbtastic.js' => array(),
     ),
     'css' => array(
-      'misc/farbtastic/farbtastic.css' => array('preprocess' => FALSE),
+      'misc/farbtastic/farbtastic.css' => array(),
     ),
   );
 
@@ -1816,14 +1818,15 @@ function _system_filetransfer_backend_form_common() {
  * Implements hook_init().
  */
 function system_init() {
+  $path = drupal_get_path('module', 'system');
   // Add the CSS for this module.
   if (arg(0) == 'admin' || (variable_get('node_admin_theme', '0') && arg(0) == 'node' && (arg(1) == 'add' || arg(2) == 'edit' || arg(2) == 'delete'))) {
-    drupal_add_css(drupal_get_path('module', 'system') . '/admin.css', array('weight' => CSS_SYSTEM));
+    drupal_add_css($path . '/admin.css', array('weight' => CSS_SYSTEM));
   }
-  drupal_add_css(drupal_get_path('module', 'system') . '/system.css', array('weight' => CSS_SYSTEM));
-  drupal_add_css(drupal_get_path('module', 'system') . '/system-behavior.css', array('weight' => CSS_SYSTEM));
-  drupal_add_css(drupal_get_path('module', 'system') . '/system-menus.css', array('weight' => CSS_SYSTEM));
-  drupal_add_css(drupal_get_path('module', 'system') . '/system-messages.css', array('weight' => CSS_SYSTEM));
+  drupal_add_css($path . '/system.css', array('weight' => CSS_SYSTEM, 'preprocess' => TRUE));
+  drupal_add_css($path . '/system-behavior.css', array('weight' => CSS_SYSTEM, 'preprocess' => TRUE));
+  drupal_add_css($path . '/system-menus.css', array('weight' => CSS_SYSTEM, 'preprocess' => TRUE));
+  drupal_add_css($path . '/system-messages.css', array('weight' => CSS_SYSTEM, 'preprocess' => TRUE));
 
 
   // Ignore slave database servers for this request.
diff --git a/modules/tracker/tracker.pages.inc b/modules/tracker/tracker.pages.inc
index 0a5a59654b366743ac838f7582488d9befec1b40..c8f7dd476a9c48d6e452014eef6f686395790204 100644
--- a/modules/tracker/tracker.pages.inc
+++ b/modules/tracker/tracker.pages.inc
@@ -113,7 +113,7 @@ function tracker_page($account = NULL, $set_title = FALSE) {
     '#theme' => 'table',
     '#empty' => t('No content available.'),
     '#attached' => array(
-      'css' => array(drupal_get_path('module', 'tracker') . '/tracker.css' => array('preprocess' => FALSE)),
+      'css' => array(drupal_get_path('module', 'tracker') . '/tracker.css' => array()),
     ),
   );
   $page['pager'] = array(
diff --git a/modules/user/user.module b/modules/user/user.module
index ef2b4b37431eed97c59ea95416d3864fccab76c0..12ed82d11c861bf7620704186a7878d3dd2e2457 100644
--- a/modules/user/user.module
+++ b/modules/user/user.module
@@ -1784,7 +1784,7 @@ function user_menu_site_status_alter(&$menu_site_status, $path) {
  * Implements hook_init().
  */
 function user_init() {
-  drupal_add_css(drupal_get_path('module', 'user') . '/user.css');
+  drupal_add_css(drupal_get_path('module', 'user') . '/user.css', array('preprocess' => TRUE));
 }
 
 /**
diff --git a/themes/bartik/template.php b/themes/bartik/template.php
index 05484660079f021d7de410671a64b20f61184d67..128c6458da67ea3a6cbca14342ca5e71cd352e69 100644
--- a/themes/bartik/template.php
+++ b/themes/bartik/template.php
@@ -23,8 +23,8 @@ function bartik_preprocess_html(&$variables) {
   }
 
   // Add conditional stylesheets for IE
-  drupal_add_css(path_to_theme() . '/css/ie.css', array('weight' => CSS_THEME, 'browsers' => array('IE' => 'lte IE 7', '!IE' => FALSE), 'preprocess' => FALSE));
-  drupal_add_css(path_to_theme() . '/css/ie6.css', array('weight' => CSS_THEME, 'browsers' => array('IE' => 'IE 6', '!IE' => FALSE), 'preprocess' => FALSE));
+  drupal_add_css(path_to_theme() . '/css/ie.css', array('weight' => CSS_THEME, 'browsers' => array('IE' => 'lte IE 7', '!IE' => FALSE)));
+  drupal_add_css(path_to_theme() . '/css/ie6.css', array('weight' => CSS_THEME, 'browsers' => array('IE' => 'IE 6', '!IE' => FALSE)));
 }
 
 /**
diff --git a/themes/garland/template.php b/themes/garland/template.php
index ad5692594181c3a0a3706813adae2abb0f7a5afa..ecd14a47e9cb24cdd35166e2282bcb0546fc2539 100644
--- a/themes/garland/template.php
+++ b/themes/garland/template.php
@@ -42,7 +42,7 @@ function garland_preprocess_html(&$vars) {
     $vars['classes_array'][] = 'fluid-width';
   }
   // Add conditional CSS for IE6.
-  drupal_add_css(path_to_theme() . '/fix-ie.css', array('weight' => CSS_THEME, 'browsers' => array('IE' => 'lt IE 7', '!IE' => FALSE), 'preprocess' => FALSE));
+  drupal_add_css(path_to_theme() . '/fix-ie.css', array('weight' => CSS_THEME, 'browsers' => array('IE' => 'lt IE 7', '!IE' => FALSE)));
 }
 
 /**
diff --git a/themes/seven/template.php b/themes/seven/template.php
index bba4930864f793c5b3f122f18a443e72ff478d4a..015a9532733b445fa6c85a4b2db7c10270c23d9e 100644
--- a/themes/seven/template.php
+++ b/themes/seven/template.php
@@ -18,9 +18,9 @@ function seven_preprocess_maintenance_page(&$vars) {
  */
 function seven_preprocess_html(&$vars) {
   // Add conditional CSS for IE8 and below.
-  drupal_add_css(path_to_theme() . '/ie.css', array('weight' => CSS_THEME, 'browsers' => array('IE' => 'lte IE 8', '!IE' => FALSE), 'preprocess' => FALSE));
+  drupal_add_css(path_to_theme() . '/ie.css', array('weight' => CSS_THEME, 'browsers' => array('IE' => 'lte IE 8', '!IE' => FALSE)));
   // Add conditional CSS for IE6.
-  drupal_add_css(path_to_theme() . '/ie6.css', array('weight' => CSS_THEME, 'browsers' => array('IE' => 'lt IE 7', '!IE' => FALSE), 'preprocess' => FALSE));
+  drupal_add_css(path_to_theme() . '/ie6.css', array('weight' => CSS_THEME, 'browsers' => array('IE' => 'lt IE 7', '!IE' => FALSE)));
 }
 
 /**