Index: form.inc
===================================================================
--- form.inc	(revision 261)
+++ form.inc	(working copy)
@@ -2016,7 +2016,7 @@
   if ($element['#autocomplete_path'] && menu_valid_path(array('link_path' => $element['#autocomplete_path']))) {
     drupal_add_js('misc/autocomplete.js');
     $class[] = 'form-autocomplete';
-    $extra =  '<input class="autocomplete" type="hidden" id="'. $element['#id'] .'-autocomplete" value="'. check_url(url($element['#autocomplete_path'], array('absolute' => TRUE))) .'" disabled="disabled" />';
+    $extra =  '<input class="autocomplete" type="hidden" id="'. $element['#id'] .'-autocomplete" value="'. check_url(url($element['#autocomplete_path'])) .'" disabled="disabled" />';
   }
   _form_set_class($element, $class);