Don't flash with the potentially bad image, use the one in post #2. Then post a screenshot of the interface if its still up while frozen.
It just happened a few minutes after I put in the new SD card with the image burned from Post #2 - here is the Miner status screen:
I have changed the voltage to 0720 with a Frequency of 200M (I think the default was set to 0725) and will test this.
Hmm, the last time I saw that error (all temps also go to 0) it was inconclusive. Are you able to SSH in during one of those states and see what the cgminer window reports? Do you have a spare PSU you can test for a few hours with [on the off chance that you have one of the PCI-E models]?