Steam game problem

Before I mention the problem, I'll list what I'm using on my pc.

CPU: INTEL CORE 2 EXTREME X6800

Mobo: ASUS MAXIMUS FORMULA SPECIAL EDITION

RAM: CORSAIR XMS2 DOMINATOR 2GB (2 x 1GB) + G.SKILL 4GB (2 x 2GB) = 6GB

Video Card: foxconn 8800GTS 640MB

Hard Drive: WD RaptorX 150gig 10,000RPM + WD 320gig 7,200RPM

Input Device: Logitech G15 keyboard(update) + G5 mouse

OS: Windows Vista Ultimate X64

Ok, here's the problem, every steam game I have, Counter Strike 1.6, Counter Strike Source, Half Life Source, and Half Life Death Match Source have a mouse problem. My mouse works perfectly fine before I run these games. Once I run these, the mouse cursor dissapear, but the game itself has no problem, I can access all the other feature/options that are accessible with a keyboard. When I exit the games, my mouse works like normal. Anyone got any solution to this?

I have a G5 and play Steam games and have not run across this. I assume you thought of this, but did you re-download and install the driver? I think there is also a firmware update for the G5. I'm not sure if it would solve your issue though.