Another Problem Report
Once again, I went into a person's page, my daughter's, and all of her wedding pictures were missing. I went to my picture folder, renamed all of her pictures from IMG0001, etc, to her wedding date and name and tried to upload some photos. About half of the photos showed up with the "duplicate" error.
How does your algorithm know it's a duplicate? Obviously, it is not by file name, and I doubt you are just going by file size. So are you using checksums? Even if you are using a checksum, you should display the two matching pictures for user verification.