Index: includes/form.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/form.inc,v
retrieving revision 1.265.2.17
diff -u -p -r1.265.2.17 form.inc
--- includes/form.inc	12 Jan 2009 16:07:23 -0000	1.265.2.17
+++ includes/form.inc	2 Mar 2009 05:39:50 -0000
@@ -139,7 +139,7 @@ function drupal_get_form($form_id) {
   // the form, passing in the latest $form_state in addition to any
   // other variables passed into drupal_get_form().
 
-  if (!empty($form_state['rebuild']) || !empty($form_state['storage'])) {
+  if (!form_get_errors() && (!empty($form_state['rebuild']) || !empty($form_state['storage']))) {
     $form = drupal_rebuild_form($form_id, $form_state, $args);
   }