ive been playing ghost recon advanced warfighter on my pc with my new club 7900gt on medium settings at 1440 + 900 widescreen 19"moniter.i get around 20 fps. in fire fights it dips to around 8 or 9 fps,ive played around with the settings but nothing i do will improve the juddery frame rate, ive tried the latest 84.56 nvidia drivers, just the same.all other games run smooth,any ideas whats wrong.