We may have a mixture of issues, e.g. buildzoid when he switched his CPU back to spec manually (as well as using a new bios with baseline implemented) his problems were solved. His CPU he reported was also unstable from day 1.
We also have a confirmed TVB problem from Intel which they say is fixed by updating the microcode. Sadly I have not seen anyone at all, try to disable TVB in the bios to see if it stabilises anything, instead lots of people manually down clocking, but not toggling TVB specifically.
Its good you thinking rationally and also think it might be a mixture of issues. Wendell and Steve made the same point as well that the earlier bios reports cannot be set aside as they may well still be relevant.
I suppose another question, just came into my head, how many of these W680 boards have the TVB microcode update? As that is an actual confirmed problem. I would like to think Wendell did ask the datacentres that question.
That TVB update was targeted for release this month. No board has received it yet afaik.