What the hell? My keyboard just died. I thought maybe it was the AT --> PS/2 converter I was using, but a replacement did not improve the situation. Then I thought maybe it was the port on my motherboard. I found a PS/2 -- > USB converter and tried that. I 'borrowed' a roommate's keyboard, and that worked just fine. Feeling quite pissed off (do you have any idea how hard it is to use a computer without a keyboard?), I took the old keyboard and shook it around a bit. The power of fear made it work again. Now I can get back to my regular life.