protected function _validateSession()
    {
        if ($this->getIsNewSession() === true) {
            $this->setSessionParam('setup_session', true);
        } elseif ($this->getSessionParam('setup_session') !== true) {
            $sNewSid = $this->_getNewSessionID();
            session_write_close();

            session_id($sNewSid);
            session_start();
            $this->setSessionParam('setup_session', true);
        }

        return session_id();
    }