Index: includes/menu.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/menu.inc,v
retrieving revision 1.293
diff -u -p -r1.293 menu.inc
--- includes/menu.inc	8 Oct 2008 01:42:16 -0000	1.293
+++ includes/menu.inc	8 Nov 2008 03:16:58 -0000
@@ -547,7 +547,7 @@ function _menu_item_localize(&$item, $ma
         $item['title'] = t($item['title'], menu_unserialize($item['title_arguments'], $map));
       }
     }
-    elseif ($callback) {
+    elseif (drupal_function_exists($callback)) {
       if (empty($item['title_arguments'])) {
         $item['title'] = $callback($item['title']);
       }