Before i get started, here are some specs.

Intel I-5 OCed at 2.9 ghz
Nvidia Geforce 460m
6 gigs of ddr3 ram

Ok, so i have played through most of fallout 3 just dealing with it, but this is getting on my nerves.

I run this game on ultra high with aa at 1980x1200 resolution with a consistent 50-60 fps (would be higher if not for fps cap). But for some reason, when i get near smoke (or fire?) my framerate drops by 35-45 fps. This is extremely abnormal. Help?

Smoke is a particle effect. What kind of smoke, from fire barrels or when doors open and such?