This just in: iCal still sucks

Almost a year to the day after the last episode, iCal ate my calendars again. The symptoms were exactly the same: iCal loads up completely blank, yet the calendar data is obviously still in there somewhere, because doing a database backup produced a directory containing about 2.5M of data. Running restore on that backup didn't work: iCal just stalled claiming the restore was in progress. I aborted it after about 10 minutes of spinning. As noted previously, deleting ~/Library/Application Support/iCal solves the problem. iCal opened up blank, and after a few minutes restored my data. (I still don't know why this works.)