Note: I got this today after I replaced some gun sounds with some sounds I stole from BF2. Can the sounds cause problems? Seriously?
its hud_dynamiccrosshair, it probably got changed to 0 somehow. either that or the weapons scripts were changed.
Playing with hud_dynamiccrosshair 0 helps with aim anyways. It's easy to memorize the general spread of the weapons, and it helps in finding the center of the screen faster.