? .htaccess
? system.admin-276615.patch
Index: modules/system/system.admin.inc
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.admin.inc,v
retrieving revision 1.63.2.8
diff -u -p -r1.63.2.8 system.admin.inc
--- modules/system/system.admin.inc	9 Jun 2009 10:58:09 -0000	1.63.2.8
+++ modules/system/system.admin.inc	16 Jun 2009 09:11:14 -0000
@@ -187,7 +187,6 @@ function system_admin_theme_settings() {
  */
 function system_themes_form() {
 
-  drupal_clear_css_cache();
   $themes = system_theme_data();
 
   uasort($themes, 'system_sort_modules_by_info_name');
@@ -263,6 +262,7 @@ function system_themes_form() {
  * Process system_themes_form form submissions.
  */
 function system_themes_form_submit($form, &$form_state) {
+  drupal_clear_css_cache();
 
   // Store list of previously enabled themes and disable all themes
   $old_theme_list = $new_theme_list = array();