Problems with Responder results

Im using a NetConnection object to make a remote call and the when the responder event fires, the event object that is returned seems to be undefined (partially) anyways.

Here’s the code:


function initMedia():void {
    connection = new NetConnection();
    connection.connect(gatewayURL);
    connection.call("media.getFiles", new Responder(mediaResult), 39);
}

function mediaResult(ev:Object):void {
    trace(ev);
    trace(ev.totalCount);
    trace(ev.target);
}

The console spits out:

A blank line
5
undefined

Does anyone know why some of the information associated with this object is defined and some of it is not?

Cheers.