Apparantly, the SD1A firmware update did more bad than good as many users are reporting that the update broke their hard drive. Dutch computer site Tweakers says the patch worked on 1TB ST31000340AS and 750GB ST3750330AS Barracuda drives but caused read errors on 500GB ST3500320AS drives.
Seagate assures users that their data isn't lost, and says they're working on a new update that should resolve all problems with the Barracuda 7200.11 series.