Loading External Video

Hi,

I am using the AS3 code below to load an external video. It is all working fine except that when i play the swf, just before the video appears a small black square flashes up on the screen and then disapears. Its only appears for a millisecond but its noticable. It looks like it could be the video itself appearing before its been scaled up to the size i want. Does anyone know why this is happening?

// ActionScript 3.0
var video:Video = new Video();
addChild(video);
 
var nc:NetConnection = new NetConnection();
nc.connect(null);
 
var ns:NetStream = new NetStream(nc);
ns.client = {};
ns.client.onMetaData = ns_onMetaData;
ns.client.onCuePoint = ns_onCuePoint;
ns.play("mountain_ad_01.flv");
 
video.attachNetStream(ns);
 
function ns_onMetaData(item:Object):void {
    trace("metaData");
    // Resize video instance.
    video.width = item.width;
    video.height = item.height;
    // Center video instance on Stage.
    video.x = (stage.stageWidth - video.width) / 2;
    video.y = (stage.stageHeight - video.height) / 2;
}
 
function ns_onCuePoint(item:Object):void {
    trace("cuePoint");
    trace(item.name + "\	" + item.time);
}

Thanks!