CONFIG_MEMTEST in kernel isn’t enabled. You could add memtest in kernel command line and have the kernel self-check your memory.
I ran Prime95 (Blend test) for 2 hours with no errors.
I am going to use stressapptest from Google to run a memory test as well.
Any other ideas/suggestions?
I do not think that the CPU, PSU or RAM are to blame but BIOS.
For me it work with Agesa 1.2.0.0 (and you have it) and XMP 2.
If it will not work for you try with Agesa 1.0.0.4.