Tank screws up and sound when i enter scope mode

[Deus Ex 0]

hey, when I enter a tank, and im the gunner, when i use the scope, and i fire, it sounds get choppy like a cheap immatation of a wav copy being recoreded from a microphone.

also when im in 3rd person in the tank in a dog fight, my game gets very laggy and my mouse prectically revereses. so up is down and down is up and left is right and right is left. i have to alt tab for it to stop doing that. i cant be alt tabbing in a middle of a dog fight.

another prob, when i try and run sideways to gain full speed, i cant press as many buttons as i was able to when i was runnins windows ME. i press buttons Shift, forward, left or right.

I run Windows XP right now, when I had windows ME i had no probs like this. i was wondering if theres someway to fix it.

i pretty much stopped playing OFP because of these probs.

your help would be greatly appreciated

im running

Windows XP home edition

Pentium 4 1.5GHZ

nVidia Geforce 2 MX/MX 400

DirectX 8.1

256 RDRAM

SoundMAX Digital Audio

[Deus Ex 0]

hmm so know one knows what the problem is huh?