Index: modules/node/content_types.inc
===================================================================
RCS file: /cvs/drupal/drupal/modules/node/content_types.inc,v
retrieving revision 1.50.2.2
diff -u -p -r1.50.2.2 content_types.inc
--- modules/node/content_types.inc	27 Apr 2009 14:28:57 -0000	1.50.2.2
+++ modules/node/content_types.inc	24 Aug 2009 20:14:29 -0000
@@ -296,7 +296,7 @@ function node_type_form_submit($form, &$
     }
   }
 
-  unset($variables['form_token'], $variables['op'], $variables['submit'], $variables['delete'], $variables['reset'], $variables['form_id']);
+  unset($variables['form_token'], $variables['op'], $variables['submit'], $variables['delete'], $variables['reset'], $variables['form_id'], $variables['form_build_id']);
 
   // Save or reset persistent variable values.
   foreach ($variables as $key => $value) {