superfly2000: Well..the game should be running in full screen as of default.
However...there is probably a change in resolution between what the game is using and what you are using on your computer. That could be the problem.
I don't think there is a super good solution to it. Perhaps you have to lower your resolution when running windows. In any case you can check in on your monitor settings...hmm...by the way....modern monitors should adapt automatically shouldn't they...
I know this might not be of super help but it is just some ramblings.
Don't know if it is relevant in your case but I am using an NVIDIA 9800GT Graphics card and I solved this problem by installing old drivers. Game works a treat now.