^i've always used the drivers that came w/ the mouse.
when i had updated to the newest driver that's currently out now, it had major issues with it.
i immediately uninstalled the newest drivers and used the original drivers that it came with, and i haven't had much problems since.
does it only happen during CS or does it happen w/ anything else?
cause it may be an internet lag issue.
what speed internet are you using? DSL, CAble, dial-up?