Index: wp-admin/categories.php
===================================================================
--- wp-admin/categories.php	(revision 12701)
+++ wp-admin/categories.php	(working copy)
@@ -116,7 +116,7 @@
 
 	$location = 'categories.php';
 	if ( $referer = wp_get_original_referer() ) {
-		if ( false !== strpos($referer, 'categories.php') )
+		if ( false === strpos($referer, 'categories.php') )
 			$location = $referer;
 	}