Index: modules/system/system.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.module,v
retrieving revision 1.844
diff -u -p -r1.844 system.module
--- modules/system/system.module	22 Nov 2009 01:33:45 -0000	1.844
+++ modules/system/system.module	27 Nov 2009 23:12:06 -0000
@@ -2557,9 +2557,6 @@ function confirm_form($form, $question, 
 
   drupal_set_title($question, PASS_THROUGH);
 
-  // Confirm form fails duplication check, as the form values rarely change -- so skip it.
-  $form['#skip_duplicate_check'] = TRUE;
-
   $form['#attributes'] = array('class' => array('confirmation'));
   $form['description'] = array('#markup' => $description);
   $form[$name] = array('#type' => 'hidden', '#value' => 1);