If you have a Kepler GPU and it is not folding, there are two problems.
EDIT: The information below (blue) is out of date. New information shown in black:
FAH Version 7.2.9 now automatically updates the information in GPUs.txt every 30 days. As of today all Kepler are listed .. at least until new ones go on the market.
The updated FahCore V2.25 does work with Kepler. If you still have V2.22, add the setting of client-type=advanced.
First, FAH V7.1.52 was released before the Kepler hardware existed and it does not recognize these GPUs unless you follow the instructions in this forum to download GPUs.txt and restart the client.
Second, the CUDA-based FahCore used to process WUs needs some important changes before it will work with Kepler. Some of these changes are being beta tested but they're not ready for release. Please be patient.
NOTE: Not all GeForce 600 series GPUs are Kepler A few are rebranded Fermi. Note the second letter in the chip's code name (e.g.- GF119 vs. GK107)