Today I had another two units come through with the same issue (they're multiplying!) and I did the same thing by replacing the crystal. It didn't work! They're adapting! Panic stricken, I remembered something else my colleague mentioned about the Super I/O
IC that's on the board, since that handles the front panel as well as coms. Took the board out, reflowed the the chip, plugged everything back in, and it worked! Until it didn't after another benchmark later on. This time around, I brought out the big guns, I took a soldering iron to that bastard chip...
Funny enough, Wikipedia has a picture of a near identical chip... http://en.wikipedia.org/wiki/File:Sm...rIO_on_IBM.JPG
Trying to solder one of those chips is... not easy. The first time I tried, there was a couple small bridges on the pins, which resulted in serial and parallel coms failing. Had to use a mix of the iron, wick, flux and hot air to get it done, but eventually proved successful. With the chip firmly soldered in place, all coms worked and the system stopped turning itself on.
This saving the planet from the robot apocalypse stuff is hard going.