I was having this problem a lot with Win 7 which I have on a fairly old desktop. I came across a comment somewhere that suggested I disable "Use Hardware Acceleration When Available". I tried this and have not had the mouse-freeze problem (touch wood) ever since. Give it a try and see if it works. If it doesn't solve the mouse problem, it's easy to re-enable. Also, I have not noticed any differences in anything else I do on the computer, so clearly disabling this feature wasn't a big deal.