I'm using PC platform Wnidows 7 64bit quad core AMD processor 8 gigs of RAM, Nivida Quadro 1400 According to some of the things I've read,there are other features that have the same requirements and I've not had any issues with them, just the Lighting Module
The most likely cause here is outdated video drivers. Go to the link below and check if your card is supported and then ensure you have the most up to date driver. If that does not fix it, attach your system information from photoshop help>system info.
I have a high end card, older, but high end. I just did a reinstall of my whole system and updated all of my drivers. The confusing thing is that the other modules that require the same thing all seem to work just fine, it's only the lighting module.
Did you try the 3 modes described in the gpu doc? basic, etc. Have you tried 3d? Blur gallery? heavy duty liquify? These are the areas that will fail if it is GPU related.That may help us troubleshoot it.
Copy your photoshop help>system info in this thread for us to take a look at and we'll see if all that looks ok.