Index: includes/form.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/form.inc,v
retrieving revision 1.265.2.10
diff -u -r1.265.2.10 form.inc
--- includes/form.inc	13 Aug 2008 23:59:12 -0000	1.265.2.10
+++ includes/form.inc	31 Aug 2008 16:32:54 -0000
@@ -119,9 +119,8 @@
     drupal_process_form($form_id, $form, $form_state);
     if ($cacheable && !empty($form['#cache'])) {
       // Caching is done past drupal_process_form so #process callbacks can
-      // set #cache. By not sending the form state, we avoid storing
-      // $form_state['storage'].
-      form_set_cache($form_build_id, $original_form, NULL);
+      // set #cache.
+      form_set_cache($form_build_id, $original_form, $form_state);
     }
   }
 
@@ -139,7 +138,7 @@
   // 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 (!empty($form_state['rebuild']) || (!empty($form_state['storage']) && !empty($form_state['submitted']) && !form_get_errors())) {
     $form = drupal_rebuild_form($form_id, $form_state, $args);
   }