[jQuery] .ajax() with dataType: 'jsonp' will not use error callback if request fails

[mrandall]

I'm using an .ajax() call to do a jsonp request to another domain.
When the user is not logged in, however, the server will return a 401
error.  Unfortunately, this causes my .ajax() call to fail _without_
calling the error callback.  Is this a known bug?  Here is my code:

      $.ajax({
        url:      appData.API.workout.get,
        data:     {date: App.formatDate(date)},
        dataType: 'jsonp',
        success:  function(json) {
          Data =  json;
          model.buildOrderedWorkout();
          myCP.Workout.View.initialize();
        },
        error:    function(xOptions, error) {

          Controller.requestError(xOptions, error);
        }
      });

Is there a way to get this request to not fail?  I also looked at the
jquery-jsonp plugin, but that didn't really work and did not return
the http status codes.

Thanks for your help,
Mike