Mouse glitch in Counter-strike

Ok I've got a random one for ya.

In Counterstrike 1.6 my mouse sticks constantly when I am looking around. It only occurs if I am holding down 'a or 'd' while looking around, and it sticks/chops across the screen, barely moving at all.
It also does not do this in any other games, like it works fine in tf2

I have tried switching mice. No dice.
I have tried switching keyboards. No dice.
I have uninstalled+reinstalled cs. No dice.
I have tried uninstalling+reinstalling the drivers for both the mouse and keyboard. No dice.

Here's the kicker, it works fine on single player.
Please help me.

lol very odd

cs 1.6 rocks.

edit - sorry for the complete lack of help....dont have a clue.