Oh, well...it looks like we've got another bug.

the onRequestComplee method is called when the handler invocation is finished. the problem is that iniside you have something like this:

 onLoadComplete.call(this, sender.get_response().get_object());

the problem is that event though the event is generated by the Sys.Net.WebRequest class, the sender parameter (1st parameter passed to the method) points to the executor that made the call. so, i should only be sender.get_object( )...