I ran Diskwarior and optimized my hard drive and it rewrote my directory. Everything seemed OK but it somehow erased my iPhoto library. Not all the photos were deleted from the drive but none appeared in iPhoto any longer.
Diskwarrior even brought back photos I had deleted in the past but any recently imported pictures from my camera are no longer on the drive at all. Is there a way to restore the previous file directory and get my pictures back?