Quote from: Big Time Coin on January 30, 2014, 01:48:13 PM

So cgminer disables the device because of libusb error, assigns a new number, but sometimes it gets stuck with this:

HFB 0: max 14C 0.58V | ZOMBIE/ 0.000h/s

and once that happens, it does not disable/re-add the device until I restart cgminer

I am seeing the similar USB issues (though not as bad to not be able to recover) especially when restarting cgminer. I am at bone stock settings running 3.12.0 off a ubuntu machine. I checked the basement to see if I could re-arrange the external fans I have setup and saw that the wife had closed the basement door, and it was getting quite warm down there.

Once I opened up the door again, it seems to be working pretty solid.
Check your ambient temperature and try to keep it cool if possible.
They say it is safe up to 85C (according to ckolivas), but I think the best bet it try to keep them under 80C.