diff --git a/cdn.basic.css.inc b/cdn.basic.css.inc
index 66cc0a3..157a5da 100644
--- a/cdn.basic.css.inc
+++ b/cdn.basic.css.inc
@@ -14,6 +14,12 @@
  * Changes: call _cdn_build_css_cache() instead of drupal_build_css_cache().
  */
 function _cdn_aggregate_css(&$css_groups) {
+  // Don't override Drupal core's aggregation if this page is not going to use
+  // a CDN anyway.
+  if (!cdn_check_protocol() && !cdn_check_drupal_path($_GET['q'])) {
+    return;
+  }
+
   $preprocess_css = (variable_get('preprocess_css', FALSE) && (!defined('MAINTENANCE_MODE') || MAINTENANCE_MODE != 'update'));
 
   // For each group that needs aggregation, aggregate its items.
@@ -22,8 +28,17 @@ function _cdn_aggregate_css(&$css_groups) {
       // If a file group can be aggregated into a single file, do so, and set
       // the group's data property to the file path of the aggregate file.
       case 'file':
-        if ($group['preprocess'] && $preprocess_css) {
-          $css_groups[$key]['data'] = _cdn_build_css_cache($group['items']);
+        if ($preprocess_css) {
+          if ($group['preprocess']) {
+            $css_groups[$key]['data'] = _cdn_build_css_cache($group['items']);
+          }
+          else {
+            $suffix = '';
+            if (count($group['items']) == 1) {
+              $suffix .= '_' . basename($group['items'][0]['data']);
+            }
+            $css_groups[$key]['data'] = _cdn_build_css_cache($group['items'], $suffix);
+          }
         }
         break;
       // Aggregate all inline CSS content into the group's data property.
@@ -44,7 +59,7 @@ function _cdn_aggregate_css(&$css_groups) {
  * - the inner loop is modified
  * - uses _cdn_build_css_path() instead of drupal_build_css_path().
  */
-function _cdn_build_css_cache($css) {
+function _cdn_build_css_cache($css, $suffix = '') {
   $data = '';
   $uri = '';
   $map = variable_get('drupal_css_cache_files', array());
@@ -78,7 +93,7 @@ function _cdn_build_css_cache($css) {
 
     // Prefix filename to prevent blocking by firewalls which reject files
     // starting with "ad*".
-    $filename = 'css_' . drupal_hash_base64($data) . '.css';
+    $filename = 'cdn_css_' . drupal_hash_base64($data) . $suffix . '.css';
     // Create the css/ within the files folder.
     $csspath = 'public://css';
     $uri = $csspath . '/' . $filename;
diff --git a/cdn.module b/cdn.module
index 5864354..1cde574 100644
--- a/cdn.module
+++ b/cdn.module
@@ -69,15 +69,9 @@ function cdn_file_url_alter(&$original_uri) {
   $mode                  = variable_get(CDN_MODE_VARIABLE, CDN_MODE_BASIC);
   $farfuture             = variable_get(CDN_BASIC_FARFUTURE_VARIABLE, CDN_BASIC_FARFUTURE_DEFAULT);
   $stats                 = variable_get(CDN_STATS_VARIABLE, FALSE) && user_access(CDN_PERM_ACCESS_STATS);
-  $file_path_blacklist   = variable_get(CDN_EXCEPTION_FILE_PATH_BLACKLIST_VARIABLE, CDN_EXCEPTION_FILE_PATH_BLACKLIST_DEFAULT);
-  $file_path_whitelist   = variable_get(CDN_EXCEPTION_FILE_PATH_WHITELIST_VARIABLE, CDN_EXCEPTION_FILE_PATH_WHITELIST_DEFAULT);
-  $drupal_path_blacklist = variable_get(CDN_EXCEPTION_DRUPAL_PATH_BLACKLIST_VARIABLE, CDN_EXCEPTION_DRUPAL_PATH_BLACKLIST_DEFAULT);
-  $auth_users_blacklist  = variable_get(CDN_EXCEPTION_AUTH_USERS_BLACKLIST_VARIABLE, CDN_EXCEPTION_AUTH_USERS_BLACKLIST_DEFAULT);
   $https_support         = variable_get(CDN_HTTPS_SUPPORT_VARIABLE, FALSE);
   $maintenance_mode      = variable_get('maintenance_mode', FALSE);
   $is_https_page         = cdn_request_is_https();
-  $module_blacklist      = cdn_get_blacklist();
-  global $user;
 
   // Don't alter file URLs when running update.php.
   if (defined('MAINTENANCE_MODE')) {
@@ -104,35 +98,13 @@ function cdn_file_url_alter(&$original_uri) {
       $uri = $original_uri;
     }
 
-    // If the current page is being served via HTTPS, and the CDN does not
-    // support HTTPS, then don't rewrite the file URL, because it would make the
-    // visit insecure.
-    if ($is_https_page && !$https_support) {
+    if (!cdn_check_protocol()) {
       return;
     }
-
-    // If the current file URI matches one of the blacklisted file paths,
-    // return immediately, except when the current file URI also matches one
-    // of the whitelisted file paths.
-    if ((
-          drupal_match_path($uri, $file_path_blacklist)
-          ||
-          drupal_match_path($uri, $module_blacklist)
-        )
-        && !drupal_match_path($uri, $file_path_whitelist)
-      )
-    {
-        return;
-    }
-  
-    // If the current Drupal path matches one of the blacklisted Drupal paths,
-    // return immediately.
-    if (drupal_match_path($_GET['q'], $drupal_path_blacklist)) {
+    if (!cdn_check_drupal_path($_GET['q'])) {
       return;
     }
-
-    // If logged in user, apply a secondary blacklist.
-    if ($user->uid > 0 && drupal_match_path($_GET['q'], $auth_users_blacklist)) {
+    if (!cdn_check_file($uri)) {
       return;
     }
 
@@ -651,6 +623,76 @@ function cdn_request_is_https() {
 }
 
 /**
+ * Check if the current protocol is supported by the CDN.
+ *
+ * Note: currently only checks HTTPS, in the future possibly also SPDY.
+ */
+function cdn_check_protocol() {
+  $https_support = variable_get(CDN_HTTPS_SUPPORT_VARIABLE, FALSE);
+
+  // If the current page is being served via HTTPS, and the CDN does not
+  // support HTTPS, then don't rewrite the file URL, because it would make the
+  // visit insecure.
+  if (cdn_request_is_https() && !$https_support) {
+    return FALSE;
+  }
+
+  return TRUE;
+}
+
+/**
+ * Check if a Drupal path should serve files from the CDN (i.e.: is the Drupal
+ * path blacklisted?).
+ *
+ * @param $path
+ *   A Drupal path.
+ */
+function cdn_check_drupal_path($path) {
+  global $user;
+  $blacklist       = variable_get(CDN_EXCEPTION_DRUPAL_PATH_BLACKLIST_VARIABLE, CDN_EXCEPTION_DRUPAL_PATH_BLACKLIST_DEFAULT);
+  $auth_blacklist  = variable_get(CDN_EXCEPTION_AUTH_USERS_BLACKLIST_VARIABLE, CDN_EXCEPTION_AUTH_USERS_BLACKLIST_DEFAULT);
+
+  // Check if the Drupal path matches one of the blacklisted Drupal paths.
+  if (drupal_match_path($path, $blacklist)) {
+    return FALSE;
+  }
+
+  // If logged in user, apply a secondary blacklist.
+  if ($user->uid > 0 && drupal_match_path($path, $auth_blacklist)) {
+    return FALSE;
+  }
+
+  return TRUE;
+}
+
+/**
+ * Check if a file should be served from the CDN.
+ *
+ * @param $uri
+ *   A file URI.
+ */
+function cdn_check_file($uri) {
+  $file_path_blacklist = variable_get(CDN_EXCEPTION_FILE_PATH_BLACKLIST_VARIABLE, CDN_EXCEPTION_FILE_PATH_BLACKLIST_DEFAULT);
+  $file_path_whitelist = variable_get(CDN_EXCEPTION_FILE_PATH_WHITELIST_VARIABLE, CDN_EXCEPTION_FILE_PATH_WHITELIST_DEFAULT);
+  $module_blacklist    = cdn_get_blacklist();
+
+  // A file should not be served from a CDN when it matches one of the
+  // blacklists, except when it matches the whitelist.
+  if ((
+        drupal_match_path($uri, $file_path_blacklist)
+        ||
+        drupal_match_path($uri, $module_blacklist)
+      )
+      && !drupal_match_path($uri, $file_path_whitelist)
+    )
+  {
+      return FALSE;
+  }
+
+  return TRUE;
+}
+
+/**
  * Helper function to efficiently load include files for this module.
  */
 function cdn_load_include($basename) {