Index: wp-includes/capabilities.php
===================================================================
--- wp-includes/capabilities.php	(revision 15608)
+++ wp-includes/capabilities.php	(working copy)
@@ -1214,7 +1214,7 @@
  */
 function is_super_admin( $user_id = false ) {
 	if ( $user_id )
-		$user = new WP_User( $user_id );
+		$user = &new WP_User( $user_id );
 	else
 		$user = wp_get_current_user();