ob_gzhandler warning error

[limitium]

if in application settings compressed is on? second call of ob_start("ob_gzhandler"); cause warning message. I know about possibility to turn off compression in plugin, but i think better way to check it.

class sfCombineUtility {

static public function setGzip() { // gzip compression if ( sfConfig::get('app_sfCombinePlugin_gzip', true) && !self::_checkGzipFail() && !sfConfig::get('sf_compressed',false) ) { ob_start("ob_gzhandler"); }
}