Have you determined that the aspx page is getting the request
and arguments you are sending?
I prefer to build the request object and invoke send in AS
rather than declaratively.
Binding directly to lastResult is hard to debug. Instead,
have the result event call a handler function. In that function,
inspect the result object to be sure you have the data and
structure you expect.
I also advise setting resultformat="e4x". Then you can do