diff -r 7f196509bf78 -r 3700f7124c2b includes/clientside/static/acl.js
--- a/includes/clientside/static/acl.js	Mon Jun 09 20:52:34 2008 -0400
+++ b/includes/clientside/static/acl.js	Tue Jun 10 00:21:34 2008 -0400
@@ -5,6 +5,10 @@
 var aclDataCache = false;
 
 // Can be set to true by slow themes (St. Patty)
+if ( typeof(pref_disable_js_fx) != 'boolean' )
+{
+  var pref_disable_js_fx = false;
+}
 var aclDisableTransitionFX = ( is_firefox2 || pref_disable_js_fx ) ? true : false;
 
 function ajaxOpenACLManager(page_id, namespace)