Index: includes/form.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/form.inc,v
retrieving revision 1.439
diff -u -p -r1.439 form.inc
--- includes/form.inc	9 Mar 2010 11:45:37 -0000	1.439
+++ includes/form.inc	11 Mar 2010 14:10:41 -0000
@@ -781,12 +781,6 @@ function drupal_prepare_form($form_id, &
  *   not be repeated in the submission step.
  */
 function drupal_validate_form($form_id, &$form, &$form_state) {
-  $validated_forms = &drupal_static(__FUNCTION__, array());
-
-  if (isset($validated_forms[$form_id]) && empty($form_state['must_validate'])) {
-    return;
-  }
-
   // If the session token was set by drupal_prepare_form(), ensure that it
   // matches the current user's session.
   if (isset($form['#token'])) {
@@ -797,7 +791,6 @@ function drupal_validate_form($form_id, 
   }
 
   _form_validate($form, $form_state, $form_id);
-  $validated_forms[$form_id] = TRUE;
 }
 
 /**