8800gts problem maybe ?

Hi

I have an e4400 @2.9, 2 gig ddr2 667 ram, a pny 8800gts 320 (tried stock and 600/900), xfx 650i mobo, a 650psu and latest nvidia drivers. I am running vista home premium 32bit.
When I play bf2 and all i get are problems, I run other games rainbow 6 vegas and stuff and have absolutley no problem. For at least a half to 2 thirds of each round my fps yoyo from 100-30 and then they stabalise again. check link http://www.youtube.com/watch?v=kQIQdxkR7gQ . As you can see from the video it isnt just when the screen gets busy. I have tried all of the visual settings, even on the lowest it still spikes like mad. I have tried running cpu and gpu at stock and still no joy. My ping and conection seem fine, never running over 50ms. My isp claim that my connection is good with no packet loss.
I can only assume its vista. everything else works fine 1100 3d06. I have tried the ms hotfix and still nothing.
If anyone can help it would be appreciated.

Thanks

3d06, as I said I have tried all graphic settings. at 1024 at the moment. tried clearing cache files in bf2 and no joy I will try v-sync

Im pretty shure its bf2, try reinstalling it. My bf2 used to run at 60+ fps constant, now runs at 60+ and then laggs for a few seconds in certain places in the map. Unfortanatly i lost my bf2 cd key and cannot reinstall.

try 162.18 driver. Just like when I played Lost Planet a while ago with 158.22, the game hung and switch back to windows. After installing 162.18, everything became fine. Hope this help.

Try to check your CPU temp and overall temp. Overclocked Intel CPU tend to slowdown when temperature reach high temp.

Disable some services on Vista which you don't need and/or third party softwares which run on the background such antivirus etc.

Can i have some source(s) who said the same thing ?