Index: includes/ajax.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/ajax.inc,v
retrieving revision 1.30
diff -u -p -r1.30 ajax.inc
--- includes/ajax.inc	28 Apr 2010 20:25:19 -0000	1.30
+++ includes/ajax.inc	29 Apr 2010 18:12:30 -0000
@@ -238,6 +238,7 @@ function ajax_get_form() {
 
   // Since some of the submit handlers are run, redirects need to be disabled.
   $form_state['no_redirect'] = TRUE;
+  $form_state['no_cache'] = FALSE;
 
   // The form needs to be processed; prepare for that by setting a few internal
   // variables.
@@ -517,6 +518,7 @@ function ajax_process_form($element, &$f
     );
 
     $form_state['cache'] = TRUE;
+    $form_state['no_cache'] = FALSE;
   }
   return $element;
 }