Index: includes/form.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/form.inc,v
retrieving revision 1.339
diff -u -p -r1.339 form.inc
--- includes/form.inc	2 Jun 2009 13:47:25 -0000	1.339
+++ includes/form.inc	3 Jun 2009 01:55:34 -0000
@@ -1419,21 +1419,21 @@ function _form_set_value(&$form_values, 
   }
 }
 
-function form_options_flatten($array, $reset = TRUE) {
-  // $reset has been ignored here as the function recurses, retaining
-  // its value while recursing and resetting itself when called.
-  static $return;
+function form_options_flatten($array) {
+  // Always reset static var when first entering the recursion
+  drupal_static_reset('_form_options_flatten');
+  return _form_options_flatten($array);
+}
 
-  if ($reset) {
-    $return = array();
-  }
+function _form_options_flatten($array) {
+  $return = &drupal_static(__FUNCTION__);
 
   foreach ($array as $key => $value) {
     if (is_object($value)) {
-      form_options_flatten($value->option, FALSE);
+      _form_options_flatten($value->option);
     }
     elseif (is_array($value)) {
-      form_options_flatten($value, FALSE);
+      _form_options_flatten($value);
     }
     else {
       $return[$key] = 1;