How does the invoke event for an Air iOS app work?

Hi,

If my app gets invoked for the first time the invoke event isn't fired.

If the app gets invoked for the second time it is working.

How to get the event.arguments[0] every time the app gets opened/invoked?

NativeApplication.nativeApplication.addEventListener(InvokeEvent.INVOKE, onAppInvoke);

function onAppInvoke(event:InvokeEvent):void {
trace("INVOKE ARGS: "+event.arguments[0]);
}

Thanks