Mouse Tracking bug? Only on the X axis? WTF?

Hello everyone!
I'm having a problem with my Halo 2 running on a x64 Vista Ultimate. What happens is that every 20 sec or so the game freaks out when moving the mouse on the x-axis too quickly (let's say trying to turn really quick when someone's shooting at your back). The mouse jerks and doesn't really move. Not only that, but my actual windows mouse icon appears on screen for a brief second and off center (i'm guessing the position where the gun should have been pointing by that time in the turn).
Weird thing is that this only really happens on the x-axis, but that might be saying little because there is little need to quickly move the mouse on the y-axis. I've tried to find a similar problem in the forums but haven't found one. Any help is appreciated, because this bug or glitch or whatever makes the game near unplayable. Thanks!

You may wanna search for mouselag but it also sounds like some other app is popping up briefly, try to close all or most apps (including tray-apps) before running the game and try again.

This happens to me. If you have ANYTHING running on your desktop when you start it up, it will happen. If you minimize any windows open before starting it up, it seems to do the trick. No issues for me without open windows.

Thanks for the quick replies!
I'll try it and see if the problem disappears.