For those who are getting clBuildProgram errors, did you reboot after applying 12.1? I have an Ubuntu box at home running 12.1 & oclHashcat-lite-0.09 just fine. My box at work is running 11.x and gets clBuildProgram error. I haven't rebooted it yet (because I have to be at the physical console to start X).
PS both machines have 5870s.
PS both machines have 5870s.