Bring everything to default in BIOS (voltages etc.). I guess you tested it with different modules and ruled out RAM as problem. If everything works fine with one module, try two, but set command rate to 2T.
They are already at stock. So Memtest86+ says there was an error on bits 0002000. Memtest 86 says the same thing. I don't know what that means.
It means there is an error, i never run memtest, so idk. You need to test one module at time, and you didn't gave us more information about what you did. It seems like a bad RAM, but it could easily be something else. You said it is good with one module, so try the same with another one.
Ok, problems showing in 2 modules as well, it just took longer. This is impossible to diagnose at this point as my AM3 hardware is already off the market. Time for a new setup.