Index: includes/menu.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/menu.inc,v
retrieving revision 1.255.2.17
diff -u -p -r1.255.2.17 menu.inc
--- includes/menu.inc	9 Jul 2008 15:23:50 -0000	1.255.2.17
+++ includes/menu.inc	21 Jul 2008 06:58:52 -0000
@@ -2203,7 +2203,7 @@ function _menu_router_build($callbacks) 
     // Extract load and to_arg functions.
     foreach ($parts as $k => $part) {
       $match = FALSE;
-      if (preg_match('/^%([a-z_]*)$/', $part, $matches)) {
+      if (preg_match('/^%([a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*)$/', $part, $matches)) {
         if (empty($matches[1])) {
           $match = TRUE;
           $load_functions[$k] = NULL;