Index: wp-admin/js/nav-menu.dev.js
===================================================================
--- wp-admin/js/nav-menu.dev.js	(revision 14325)
+++ wp-admin/js/nav-menu.dev.js	(working copy)
@@ -251,7 +251,7 @@
 					var activePanel,
 					panelIdMatch = /#(.*)$/.exec(e.target.href),
 					tabPanels,
-					wrapper = getParentWrapper(e.target, 'inside'),
+					wrapper = $(e.target).parents('.inside').first()[0],
 					inputs = wrapper ? wrapper.getElementsByTagName('input') : [],
 					i = inputs.length;