Sometimes when I start up Far Cry 2, the movement is very jittery / choppy, whatever you want to call it. It's like taking 2 steps forward, one step backward. My framerate is what it's normally at, (~30) and even when I put the settings as low as possible I still get this choppiness. Also when I reload a gun, it seems to play the reloading animation and sound 10 times at once.

After restarting my computer, it will run fine. For the first time at least. After starting up FC2 again it will be jittery again. It seems to get worse every time I start it up, but then restarting my computer seems to 'fix' it for the next time I play only.

It also does this in the Map Editor. Framerate is fine, but movement looks like I'm having a seizure.

What can I do to fix it? Is anybody else getting this problem? It only happens with Far Cry 2.

So far, as suggested by Ubisoft's support, I have tried:
-Closing all programs running in the background (by going into MSCONFIG and doing a selective startup)
-Virus Scan
-Defrag
-Reinstalling the game
-Scandisk
-Update DX files
-Update graphics card drivers
-Update sound card drivers
-Remove files from the temp. directory
-Update BIOS

None of these have fixed it, I still get the problem.

My computer is running:
Windows XP Media Center Edition (with SP3)
4GB RAM
GeForce 9600GT
AMD Athlon 64 x2 Dual Core Processor 4600+
Onboard Realtek HD audio
Also, this is the steam version of Far Cry 2

If you need any more info I can probably give it to you.

Have you installed the AMD optimizer and the driver? http://support.amd.com/us/psea...Download%20Processor

Nope, going to try that now.