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	12 Sep 2008 13:27:59 -0000
@@ -294,6 +294,7 @@
   $args = func_get_args();
   $form = call_user_func_array('drupal_retrieve_form', $args);
   $form['#post'] = $form_state['values'];
+  _form_set_current($form);
   drupal_prepare_form($form_id, $form, $form_state);
   drupal_process_form($form_id, $form, $form_state);
 }
@@ -561,12 +562,6 @@
  *   not be repeated in the submission step.
  */
 function drupal_validate_form($form_id, $form, &$form_state) {
-  static $validated_forms = array();
-
-  if (isset($validated_forms[$form_id])) {
-    return;
-  }
-
   // If the session token was set by drupal_prepare_form(), ensure that it
   // matches the current user's session.
   if (isset($form['#token'])) {
@@ -575,9 +570,7 @@
       form_set_error('form_token', t('Validation error, please try again. If this error persists, please contact the site administrator.'));
     }
   }
-
   _form_validate($form, $form_state, $form_id);
-  $validated_forms[$form_id] = TRUE;
 }
 
 /**
@@ -788,13 +781,14 @@
  */
 function form_set_error($name = NULL, $message = '') {
   static $form = array();
-  if (isset($name) && !isset($form[$name])) {
-    $form[$name] = $message;
+  $build_id = _form_set_current();
+  if (isset($name) && !isset($form[$build_id][$name])) {
+    $form[$build_id][$name] = $message;
     if ($message) {
       drupal_set_message($message, 'error');
     }
   }
-  return $form;
+  return $form[$build_id];
 }
 
 /**
@@ -1325,6 +1319,27 @@
 }
 
 /**
+ * Stores the current form id, generating it if missing
+ *
+ * @param $form
+ *   The curren form
+ * @return
+ *   The current id
+ */
+
+function _form_set_current(&$form = NULL) {
+  static $current = 'current';
+  if (isset($form)) {
+    // FIXME: is #current_build_id really needed or we can use #build_id instead?
+    $current = isset($form['#build_id']) ? $form['#build_id'] : $form['#current_build_id'];
+    if (empty($current)) {
+      $current = $form['#current_build_id'] = 'form-'. md5(uniqid(mt_rand(), TRUE));
+    }
+  }
+  return $current;
+}
+
+/**
  * Retrieve the default properties for the defined element type.
  */
 function _element_info($type, $refresh = NULL) {