iPhoto 4 unexpectedly quits when opened: "... delete
1. Insufficient disk space when exporting
2. Quit when open
I'd guess it would fix the disk space problem for iPhoto 2 as well. That problem is apparently due to thumbnail corruption.
update: this didn't work for me. I had to use Panther Cache Cleaner to do a deep cache removal. See my posting of 5/1/04.