Index: form.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/form.inc,v
retrieving revision 1.265.2.7
diff -u -p -r1.265.2.7 form.inc
--- form.inc	25 Jun 2008 09:58:09 -0000	1.265.2.7
+++ form.inc	20 Jul 2008 10:47:57 -0000
@@ -1419,7 +1419,13 @@ function form_select_options($element, $
       else {
         $selected = '';
       }
-      $options .= '<option value="'. check_plain($key) .'"'. $selected .'>'. check_plain($choice) .'</option>';
+      if (empty($selected) && isset($element['#disabled_values']) && in_array($key, $element['#disabled_values'])) {
+        $disabled = ' disabled="disabled"';
+      }
+      else {
+        $disabled = '';
+      }
+      $options .= '<option value="'. check_plain($key) .'"'. $selected . $disabled . '>'. check_plain($choice) .'</option>';
     }
   }
   return $options;