So it turned out that the HD was bad. Probably a factory defect. I feel a little better knowing that I didn’t do something to kill it, but there was well over a month of work on it that’s now gone.
On the bright side, Apple was good enough to give me a new PowerBook to go home with. They agreed that a HD problem like that less than a month after I got the thing was probably a defective unit and not something more sinistar.
So, now I’m at home with the replacement 12″ PB. Gonna be a “fun” evening of reloading a bunch of software and tweaking stuff out…again.