Why is my COD4 lagging?

[phoenix777]

I have a fairly good rig but my COD4 lags pretty bad for some reason... any help?

Windows 7 64 bit
i7 920
GTX 285 in SLi
6GB RAM

I can play almost all games on all max with no lag but COD4 lags me? what?
I have 2 monitors so I can monitor my CPU+GPU while playing, and I see them spiking and overloading while I'm in the game. This problem is kinda random too for some reason.

 

[Gman450]

Did you try re-installing the game ?
Are your drivers up to daye?
Which other games do you play ?