TYPO3: Powermail's solution of enable USER_INT

/**
* Switch from USER to USER_INT if a piVar is given
*
* @return   boolean     Was switched?
*/
private function switchToUserInt() {
    if (count($this->piVars) || $this->conf['caching'] != '1') { // if any GET or POST param given
        $this->cObj->convertToUserIntObject(); // Convert object to user_int (do not cache it)
        if ($this->cObj->getUserObjectType() == 2) { // if USER
            return true; // stop process (avoid double output)
        }
    }
    return false;
}