буферизация NetStream

[zzz_dmg]

подскажите, почему не работает NetStream.Buffer.Empty?

stream_ns.onStatus = function(motion_status:Object):Void  {
	if (motion_status.code == "NetStream.Buffer.Empty") {
		_root.attachMovie('buf_mc', 'buf_mc', 100, {_x:150, _y: 133});
	}
	if (motion_status.code == "NetStream.Buffer.Full") {
		_root.buf_mc.removeMovieClip();
	}
}