Recording webcam: video quality/audio sync problems

I wrote a custom Flex application to publish the stream.  Most of the code I copied from Adobe examples.  To start the camera:

var camera:Camera = Camera.getCamera();

    if (camera != null) {
        camera.setMode(320,240,30,true);
        camera.addEventListener(ActivityEvent.ACTIVITY, activityHandler);

        video = new Video(camera.width, camera.height);
        video.attachCamera(camera);

        var spriteWrapper:UIComponent = new UIComponent();
        addChild(spriteWrapper);
        spriteWrapper.addChild(video);
       
    } else {
        Alert.show("You need a camera.");
    }

The actual publishing part is here:

    nc = new NetConnection();
        nc.addEventListener(NetStatusEvent.NET_STATUS, onNetStatus);
        nc.connect("rtmp://myserver.compute.amazonaws.com/jsd");
        var client:Object = new Object();
        client.onBWDone = function ():void { trace('on bw done'); }
        nc.client = client;

private function onNetStatus(event:NetStatusEvent):void {
    if(event.info.code == "NetConnection.Connect.Success"){
        cam = Camera.getCamera();
        mic = Microphone.getMicrophone();
        mic.rate = 22;
        ns = new NetStream(nc);
        ns.attachCamera(cam);
        ns.attachAudio(mic);
        ns.publish("camtest", "record");
    }
    if (event.info.code == 'NetConnection.Connect.Rejected' || event.info.code == 'NetStream.Record.NoAccess') {
        Alert.show("Rejected");
        nc.close();
    }
}