Recently while running fsck, I ran into numerous "overlapped extent allocation (file xxxxx)" errors. fsck was unable to fix these errors. After reading in several forums that the only way to get rid of these errors is to buy DiskWarrior and rebuild the drive structure, I went to try something else, and succeeded.
I remembered that I had recently force-quit Chimera [robg adds: now called Camino] a few times, and that this could have made my cache files corrupt. I then removed the entire Chimera directory in the Application Support folder of my Library, and checked my drive again.
Voilá, no more unrepairable errors. Of course I remembered the thing with Chimera only after having copied almost all other directories from the drive :-). Does anyone know how to find out which files are affected by taking the xxxxx identifier from the fsck error messages?
Mac OS X Hints
http://hints.macworld.com/article.php?story=2003030211331230