diff -r 6ba792bc9071 -r 4d0d5dae61e5 includes/sessions.php
--- a/includes/sessions.php	Tue Jun 10 10:51:44 2008 -0400
+++ b/includes/sessions.php	Sat Jun 14 22:01:24 2008 -0400
@@ -3091,7 +3091,7 @@
    * @return array
    */
    
-  function acl_merge($perm1, $perm2, $is_everyone = false, &$defaults_used)
+  function acl_merge($perm1, $perm2, $is_everyone = false, &$defaults_used = array())
   {
     $ret = $perm1;
     if ( !is_array(@$defaults_used) )