Index: includes/theme.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/theme.inc,v
retrieving revision 1.615
diff -u -p -r1.615 theme.inc
--- includes/theme.inc	26 Sep 2010 23:31:35 -0000	1.615
+++ includes/theme.inc	28 Sep 2010 18:10:34 -0000
@@ -581,11 +581,7 @@ function list_themes($refresh = FALSE) {
     // Also check that the site is not in the middle of an install or update.
     if (!defined('MAINTENANCE_MODE')) {
       try {
-        foreach (system_list('theme') as $theme) {
-          if (file_exists($theme->filename)) {
-            $themes[] = $theme;
-          }
-        }
+        $themes = system_list('theme');
       }
       catch (Exception $e) {
         // If the database is not available, rebuild the theme data.