I wonder if the card just doesn't meet the required specs for CUDA acceleration within PP.
Officially it doesn't, but according to everything I've read, many other people have unlocked the same card and used it without issue. I just wondered if I was missing something simple in the set up.
Two things if you are going to be using an unsupported card.
First, make sure it has at least 1 GB of VRAM. If it doesn't, it will not work.
Second, you actually have to go through the unsupported cards hack. It is not supported officially, but instructions are VERY common in the forums. Here is a thread that has info on the hack. http://forums.adobe.com/message/4840565#4840565