I'm trying to OC my EVGA 7600GS with Ati tools. I updated my drivers and now when I open up Ati tools, the low power 3d clock is at 0 Mhz. My 2D and 3D are at default clock. I can't change the low power 3d clock speeds. Is the newest forceware drivers blocking OCing for the low 3d power clock?

try using nTune to overclock the card, i had to do this with my 8800gts.
i had the same thing happen with the ATITool, it showed 0 core mhz / 0 memory mhz

you can get nTune here: http://www.nvidia.com/object/ntune_5.05.54.00.html
its strait from nvidia, so its safe to use, just dont over do it.

Yeah, use "nTune" with Nvidia based graphics processors. I think ATI would be compatible with AMD/Radeon/ATI based graphics cards.