Index: modules/system/system.js
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.js,v
retrieving revision 1.40
diff -u -p -r1.40 system.js
--- modules/system/system.js	30 Jan 2010 00:29:10 -0000	1.40
+++ modules/system/system.js	30 Sep 2010 15:07:12 -0000
@@ -64,7 +64,7 @@ Drupal.cleanURLsInstallCheck = function 
     dataType: 'json',
     success: function () {
       // Check was successful.
-      $('#edit-clean-url').attr('value', 1);
+      $('input[name=clean_url]').attr('value', 1);
     }
   });
 };