Meh I screwed something up on 3.12.1 that would make cgminer just go idle eventually, so I've posted a hotfix 3.12.2 release.
Thanks! I still get an insanely long reset time though (minutes instead of seconds), while cgminer 3.12.2 is contemplating pages of these messages:
I believe you are not on new firmware? I strongly advise people wait till they have new firmware as the new cgminer code is optimised around it and vice versa.