=== modified file 'modules/menu/menu.admin.inc'
--- modules/menu/menu.admin.inc	2007-11-26 16:36:42 +0000
+++ modules/menu/menu.admin.inc	2007-12-05 22:50:02 +0000
@@ -324,6 +324,11 @@ function menu_edit_item(&$form_state, $t
  */
 function menu_edit_item_validate($form, &$form_state) {
   $item = &$form_state['values']['menu'];
+  $normal_path = drupal_get_normal_path($item['link_path']);
+  if ($item['link_path'] != $link_path) {
+    drupal_set_message(t('The menu system only supports non-aliased paths, so %link_path has been changed to %normal_path', array('%link_path' => $item['link_path'], '%normal_path' =>  $normal_path)));
+    $item['link_path'] = $normal_path;
+  }
   if (!menu_path_is_external($item['link_path'])) {
     $parsed_link = parse_url($item['link_path']);
     if (isset($parsed_link['query'])) {