I purchased a modified GeForce 8800 GT 1gb graphics card that is specific for a 2006 Mac Pro 1.1, that will enable Mercury Playback Engine. I had everything working on Snow leopard, but recently upgraded to Lion. (Mountain Lion is not supported on my Mac)
Here is a screen shot of my computuer specs, my GPU specs in Terminal, my CUDA driver Version, the error I get when launching After Effects (MPE doesn't work in Premiere Pro either, but doesn't show an error message, just greyed out) and the raytracer_supported_cards.txt documents for both Premiere Pro and After Effects in terminal. My graphics card isn't supported for for MPE because it isn't on their list, but once it's added, it works. I did this work around in Snow leopard, and got everything to work. Just with switching over to Lion, it has stopped.
I upgraded my CPU's to Intel x5355, 8 cores total
