Ciao , cosi' ottieni il loop:
...
..
.
var connection_nc:NetConnection = new NetConnection();
connection_nc.connect(null);
var stream_ns:NetStream = new NetStream(connection_nc);
my_video.attachVideo(stream_ns);
stream_ns.play("video.flv");
stream_ns.seek(0);
stream_ns.play();
//loop
stream_ns.onStatus=function(infoObject){
if(infoObject.code=="NetStream.Play.Stop"){
stream_ns.seek(0);
stream_ns.play();
}
};

...
..
.

se puo' esservi ANCORA UTILE....