Index: includes/menu.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/menu.inc,v
retrieving revision 1.255.2.20
diff -u -p -r1.255.2.20 menu.inc
--- includes/menu.inc	23 Sep 2008 10:22:35 -0000	1.255.2.20
+++ includes/menu.inc	5 Oct 2008 19:23:52 -0000
@@ -335,7 +335,7 @@ function menu_execute_active_handler($pa
   if (_menu_site_is_offline()) {
     return MENU_SITE_OFFLINE;
   }
-  if (variable_get('menu_rebuild_needed', FALSE)) {
+  if (variable_get('menu_rebuild_needed', FALSE) || !variable_get('menu_masks', array())) {
     menu_rebuild();
   }
   if ($router_item = menu_get_item($path)) {