function get($object_id, $preserve_keys = false)
 {
     if (!$this->systemerror) {
         $retval = $this->_getvalue($object_id);
     } else {
         $retval = NULL;
     }
     if ($retval === NULL) {
         $this->lastgetoid = $object_id;
         $retval = parent::get($object_id, $preserve_keys);
     }
     return $retval;
 }