Weird… I’m going to quote from a mail I sent:
In anycase, these have been some of the weirdest hardware moments I’ve ever had: it seems that an existing 32MB DIMM was right on the edge of giving up at the moment that I installed a new 128MB DIMM in the firewall and converted it to reiserfs.
It was on the edge in such a manner that it survived 12 consecutive passes of complete memtest86 test-sets (and 40 3-parallel process kernel compiles without a sig11)…. this morning however, the BIOS caught a memory error at bootup (the machine had crashed during the night); a subsequent run of memtest86 caught the error within the first 30 seconds. I’ve established with some DIMM-swapping that the problem is with the DIMM and not the slot it was in.
So, the DIMM was in the process of dying as it were… it was being sporadically flakey at a time when many variables were being added to the equation, which made the fault all the more difficult to confirm.