I've had that issue when installing new ATI drivers. I always have to run the driver cleaner and blow away the leftover registry data (including the monitor device ID's or eyefinity doesnt work). Every ATI driver update install seems to end up as an hour long troubleshooting affair for me.

I miss those 3DFX days, these days its all unified driver packages and expecting end users to understand what tessallation is. It seems the graphics heavies attempted to simplify but only succeeded in over-complicating everything.

5970 + 2 x 5870 (quad SLI) get great scaling with radeon pro lost planet profile in full screen mode. Introduces some stutters when there is a big texture swap on complex maps, but have recently learnt that this is because of the serial design of crossfire and the amount of bandwidth on the crossfire bridge.

Apparently the xfire bridge bandwidth is only designed for tri-fire when using maximum Vram. I would probably get a smoother result with trifire with this game as it uses all 1GB Vram and more, and because of the serial xfire bridge it cant swap all the textures out without a hitch!

Nvidia uses a parallel setup on their SLI bridge which reduces stutters for large texture swaps with large Vram games in SLI mode. Next upgrade for me will be quadsli GTX580 3GB cards or next gen Nvidia in Sept if its out in time.

With my HD5970 I get unplayable FPS when Fullscreen is activated, with pseudo mode on, everything is smooth.