I suspect you are right Dave. Under the details of the unexpectedly crashed - in the “JournalErrors” section is this line “…Kernel microcode:AMD CPU family 0x6 not supported” [i just found this]
EDIT…I tried changing bios settings concerning ACPI, but it didn’t change the stability while using ATI graphics with this board. It is a weird board. Takes 4GB of memory, but if you put that much in…very few graphics cards will post. I’m not sure why that is. I found a post from 2006 on 2cpu.com where a guy pulled a stick of ram and all his graphics problems were magically cured. So in desperation I tried it. Suddenly all the cards i had tried before and had failed to post - worked?
Maybe the bios can’t map that much memory. I added a 256mb of registered ECC to the fourth slot (the other three with 1 gb sticks) and it still works great.