Index: wp-admin/js/list-table.dev.js
===================================================================
--- wp-admin/js/list-table.dev.js	(revision 16472)
+++ wp-admin/js/list-table.dev.js	(working copy)
@@ -188,8 +188,13 @@
 	$('th a').click(function() {
 		var orderby = $.query.GET('orderby'),
 			order = $.query.GET('order'),
-			$th = $(this).parent('th');
+			text = $(this).text();
 
+		var $th = $(this).closest('table').find('th').filter(function(i) {
+			return $(this).text() == text;
+		});
+
+
 		if ( $th.hasClass('sortable') ) {
 			orderby = $.query.load($(this).attr('href')).get('orderby');
 			order = 'asc';