EUREKA.
I followed your suggestions and they solved the problem. I ran Memtest, first for one hour and 7 passes on test #6 (which created all of the failures before) and then for 7 hours and 10 passes on all tests - all without error.
The MCH OverVoltage Control I left on +0.1 as I could only increment in units of 0.1 so I could not go to 0.125 or 0.15.
I now get a warning on my BIOS screen - the System Voltage Control header changed to a flashing red warning "System Voltage NOT Optimized". Is it safe to continue ignoring this?
Regarding the BIOS version, I went to F8b thinking that since F8a, the version I needed for Wolfdale was still beta, any immediate problems Gigabyte had with it might have been fixed in the release of F8b. However I now see this might have ignored any new issues created in F8b. Since it now seems to work ok - at least thus far with the memory changes - do you think I should stick with it or change to F8a to be safe? If they make final changes to F8a to make it non-beta, will they just take the beta label off it or issue it as a new number? I assume if they issue a higher number non-beta I should flash it, but if they just take the "beta" designation off, will it have changes that I need to flash?
How can I measure the effective speed of my memory to have some idea or measure of the impact of the current setting changes and the future ones as I roll back the higher numbers?
Regarding the unit by unit rollback of the higher settings, any suggestions on which I should try first? Any special pairings or relationships that I should be cognizant of?
Thank you for all of your help.
I hope Gigabyte appreciates all the RMA's you've saved them from. I am more than a little surprised that when I purchase a mobo from them for a CPU they say it supports, I find it only supported with a beta bios. And then to select memory off the Qualified Vendor list by part number and have these problems is not what I expected - particularly given what appear to be known issues. Perhaps you could suggest (if you have not already) that they remove this memory from the list. I know this board is being replaced by an energy efficient one, does it seem to have the same problems with the Crucial Ballastix memory? I see Crucial does not even list this board (it lists rev 1.0 but not 2.0) in its memory selection tool.
I bet you have made a lot of friends on this forum. Ever think of running for President? We could use a good man - oops - person - who knows how to troubleshoot and tweak things to make them work. Someone who knows how to make the all the pieces work together.
rockyjohn