FPS leak after a few hours of gameplay

Same issue here. From 40-30fps, drops till 20-9fps. Lowered the resolution, graphics settings, the fps NEVER increase nor decrease at all.

I'm experiencing the FPS leak as well. It happens after a few hours of gameplay. Not sure what's causing it.

Same problem here.

I've experienced a very similar problem today was playing for a couple of hours with avg 40 - 50fps then all of a sudden it dropped to 1 - 2fps, had to restart the game which fixed the problem.

Same exact issue I'm having. I get around 60 fps when I start in the warpgate. I run out for a while to a big fight and it drops to 20-30, and then never goes above 40 even after going back to the warpgate. I tried switching continents and back but it didn't help. Logging out and back in also didn't help and was still at 30-40 fps and still feels sluggish. I then quit the game and loaded it again, and bam 60 fps in the warpgate. Every time.

Phenom II x4 965
GeForce GTX 470

Well.. now that we all know that we have the same problem... How do we fix it?

Do you have a separate profile set up for PS2 in your Nvidia control panel?
Do you have Power Management mode set to prefer max performance?