I've been rolling old archives forward to fend off losing older files due to application and OS changes. This includes unzipping, untarring, unSITing, etc. I had pretty good luck til I hit a .zip file I created some years ago, probably on an SGI, but might have been Windows NT with WinZip. Anyway, it's damaged now. Neither Stuffit 7.0.3 under Panther 10.3.9, nor WinZip (version?) under XP, would open this file.
Stuffit would act like it was working for a few seconds, then crash, leaving me with the "Submit to Apple" dialog.
In desperation, I downloaded the trial version of AZR (Automated Zip Repair) for the PC, which will only do 3MB archives in the demo mode. So I chopped up my archive with vi (bonus hint: search for "PK^C" to locate the start of each file) and recovered all but the bad file that was causing all the grief, and one adjacent file that was damaged.
Today, I was backing up the project to a hybrid DVD/DVD-ROM with iDVD. When I dragged the project directory into the DVD-ROM contents dialog box, lo and behold, there were several hidden directories with names starting with .BAHtemp-xxx-xxxxxxxxxx (the numbers varied with no obvious meaning). When I opened up one of these directories, inside were all the files that Stuffit had in fact recovered before crashing. Icons, subdirectories, everything neatly in place. Arggh! At least, I think they were from Stuffit; I had also tried plain ol' gunzip, uncompress, etc. with no success.)
So, moral of the story: always try ls -a on your directories if Stuffit crashes while opening an archive. You might get lucky!
[robg adds: As noted below in a comment by fds, it was unzip that created the hidden directories, not StuffIt. Sorry for the errors.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20050627193041148