Wow!!!!! Thank you so much! That seems to have taken care of the problem. My XPro is back to maximum stability. I tried it about 6 or 7 times. Only time will tell.
I did uninstall the Intellipoint driver (odd that I would be using that mouse) and the problem went away. AND my Intellimouse still works - all the buttons. That's even more strange.
I will keep experimenting and post here later with an update on my stability.
Thanks to all who contributed to help solve this, especially Daniel and Bill.
Scotty - Are you too using the Intellimouse?