Disk Warrior is great... but keep your fingers crossed that it works properly. DW4 has some quirky bugs that remain unfixed. As to when they will be fixed? Well, the developer didn't even bother - for almost 18 months! - fixing DW3 and leaving it to the Mac community to come up with a solution (you had to rename a sound file in DW3 if I remember correctly). Then DW4 came out... and with it a new problem.

I get often error 2163 whereas a duplicate disk cannot be put away. This happens when the "replace" button in the report is not clickable, leaving only the option to press "cancel." Great product, truly bad support.