FLVPlayback fail to invoke callBack onMetaData

programming flash
1

i’m using FLVPlayback in order to load a movie.
i keep getting this error:
Error #2044: Unhandled AsyncErrorEvent:. text=Error #2095: flash.net.NetStream was unable to invoke callback onMetaData. error=ReferenceError: Error #1069: Property duration not found on Number and there is no default value.

if i get it right, it means that inside built-in onMetaData there is no duration property.
so, i tried adding my own call back function:

//creating a custom client
var customClient:Object = new Object();
customClient.onCuePoint = cuePointHandler;
customClient.onMetaData = onMetaData;
customClient.onPlayStatus = onPlayStatus;

//loading the movie
_flvPlayback.source = url;

//replacing the custom client
_flvPlayback.getVideoPlayer(videoPlayerIndex).netStream.client = customClient;

private function onMetaData(m:Object):void {
trace("m.duration " + m.duration);
}

and its tracing the duration!!! >>

m.duration 8.05

and i keep getting the same error…:diss:

any suggestions?..