I'm playing this on Windows XP (retro) as it was intended but during play, when I look around, every two seconds, the mouse freezes for half a second making the game unplayable. It's odd because, while it freezes, the camera will suddenly snap ahead as if the mouse HAD moved. It's NOT a game freeze, however, since everything else still moves smoothly in the background.

System:
i5-2500k
3GB memory
Ati HD 4850

I tried changing the affinity of the CPU and setting compatibility but it doesn't help.