First things to try:
1) Make sure your graphics drivers are up to date.
2) Make sure there is no strange setting in the driver controls. For example something force AA, vsync, etc.
3) Try turning down the resolution.
It might also have to do with the refresh rate. U could use a tool called refreshlock and make sure the game uses some refresh rate that your monitor likes.
http://www.pagehosting.co.uk/rl/
Since WIndows 7 was nota available when the game was released, we never test for that. So not sure how well it works, but as far as I know about Windows 7, there should not be much difference from Vista. Still might be something wierd with the OpenGL drivers.