Thanks for the insight Sarcophilus!
I do already have my mouse acceleration turned off. I think the problem might actually have to do with how autohotkey simulates mouse movement… it just doesn’t seem to work quite right. I have also tried to use the record feature, but I can’t seem to get it to record my mouse movement.
I did find another program which records mouse movement and provides playback. This program worked fairly well… unfortunately it was just a demo and it wouldn’t let me edit the scrip. But XIM interpreted the playback just as if I was moving the mouse myself… well sort of… again once the mouse hit the edge of the screen, XIM stopped interpreting the mouse.
There are a few other programs which I found but haven’t tried yet. Hopefully this weekend I will find something that works and finally be able to gather some data.