===================================================================
--- includes/menu.inc   (revision 15)
+++ includes/menu.inc   (working copy)
@@ -963,10 +963,10 @@
  * @param $pid
  *   The root item from which the active trail must descend.
  */
-function _menu_get_active_trail_in_submenu($pid) {
+function _menu_get_active_trail_in_submenu($pid, $reset = FALSE) {
   static $trails;

-  if (!isset($trails)) {
+  if (!isset($trails) & !$reset) {
     // Find all menu items which point to the current node and for each
     // follow the parents up the chain to build an active trail.
     $trails = array();