So after a while of things randomly crashing, I let memtest86+ run overnight, and it found errors.
I enabled the "badram" error output, but every few seconds it shows me a differing selection of memory locations:
badram=0x14000000,0xfc000800,0x11000000,0xf9000000,0x00000000,0xe2000000,
0x12000000,0xfb000000,0x10000000,0xf8003000,0x0a000000,0xea000000,
0x20000000,0xe0000000,0x40000000,0xe0000000,0x60000000,0xf0000000,
0x70000000,0xf8000000
badram=0x14000000,0xfc000800,0x11000000,0xf9000000,0x00000000,0xe2000000,
0x12000000,0xfb000000,0x10000000,0xf8003000,0x0a000000,0xea000000,
0x20000000,0xe0000000,0x40000000,0xc0000000
My understanding is that I should be able to take that output and put it into GRUB2's configuration. I see the configuration option; I know where to put it. But... there are two different badram values reported? Which do I use? Obviously I don't understand the output.
I will buy new RAM, but would still like to do this as a temporary solution.
(I am running Ubuntu 12.10 BTW.)