I'm not talking about framerate.

I was playing a demo of serious sam and the gameplay was pretty fast paced. Sam moved pretty fast, and so did enemies. I took a break from that to play ArmA and had to update my directx and such to play it. When I come back to play serious sam it's like, average first person shooter speed.

Don't know what happened. All the weapons seem to fire at the same rates and such, it's just the movement speed.

You checked any youtube gameplay videos to make sure your memory's not playing tricks on you?