Index: includes/form.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/form.inc,v
retrieving revision 1.514
diff -u -p -r1.514 form.inc
--- includes/form.inc	8 Dec 2010 06:55:01 -0000	1.514
+++ includes/form.inc	10 Dec 2010 18:46:22 -0000
@@ -3358,7 +3358,7 @@ function form_validate_machine_name(&$el
   // Verify that the machine name is unique.
   if ($element['#default_value'] !== $element['#value']) {
     $function = $element['#machine_name']['exists'];
-    if ($function($element['#value'])) {
+    if ($function($element['#value'], $form_state)) {
       form_error($element, t('The machine-readable name is already in use. It must be unique.'));
     }
   }