Ошибка

$this->_FilePointers[$fp] = $fp;
return (!empty($str))?unserialize($str):array();
}

/*
_Write _Read2Write
*/

function _Write(&$fp,$arr) {
fseek ($fp,0);
ftruncate ($fp,0);
fwrite($fp,'<?die;?>'.serialize($arr));
fflush($fp);
flock($fp,3);
fclose($fp);
clearstatcache();
unset($arr,$this->_FilePointers[$fp]);
return;
}

$this->_FilePointers[$fp] = $fp;

$this->_FilePointers[(int) $fp] = $fp;