Index: wp-includes/nav-menu-template.php
===================================================================
--- wp-includes/nav-menu-template.php	(revision 17105)
+++ wp-includes/nav-menu-template.php	(working copy)
@@ -426,7 +426,10 @@
 					'taxonomy' == $parent_item->type &&
 					isset( $possible_taxonomy_ancestors[ $parent_item->object ] ) &&
 					in_array( $parent_item->object_id, $possible_taxonomy_ancestors[ $parent_item->object ] ) &&
-					$parent_item->object_id != $queried_object->term_id
+					(	
+						! isset( $queried_object->term_id ) ||
+						$parent_item->object_id != $queried_object->term_id
+					)
 				)
 			)
 		) {