Windows Aero = Mouse lag

Hey,

I noticed that when I run games I tend to get very little mouselag. It is not very noticeable, but can get annoying at times, especially if it's a game that caps my FPS, like MW2. I experience this mouse lag especially if I run the game in windowed mode.

By turning off Windows Aero my games run a lot smoother. I don't think that it has to do with my hardware, because I'm sure it can handle Windows Aero.

My specs:
Intel Q6600 @ 3.0 Ghz
ATI Radeon HD4870
Samsung F1 Spinpoint 1TB x3
4GB RAM

My temps are cool so that should not be the problem.

Is there any way to fix this or am I forced to either live with it or turn off Windows aero permanently?

Thanks in advance!

PS: Is there any way I can enable Windows Basic theme for certain applications? IE making my explorer turn on the Windows Basic theme when I for example start Call of Duty 4.

PS #2: Is it possible to choose what color you want for the Windows Basic theme, or can you just use that not so good-looking blueish color?

Thanks for the replies, especially yours Grimhowl. This was very helpful and solved my problem. I had made .bat files which starts a Windows Basic theme and then the specified .exe file to run, but it was clumbsy and did not reset to my normal theme after closing the application.

Thank you again, my problem has been solved!