Uh oh, the boot drive on the computer at home has decided to disappear. I don't know if it was something I did when I put in a new DVD drive, or if it just happened to be a coincidence. BIOS claims there's nothing attached to any of the on-board IDE channels, so it's either a problem with the cabling, the drive or the motherboard is pooched. Computer POSTs fine, so I don't think it's the motherboard. I may have knocked something loose putting in the drive.
Time to crack the case open again and check things out.