-- fix a bug that hanged zuluMount-gui on failed attempt at unlocking a plain dm-crypt volume at a none zero offset.a plain dm-crypt volume at
a none zero offset can be used as a hidden volume ala TrueCrypt hidden volume feature.No protetcion of hidden volume though.
More info on this functionality can be found here: https://code.google.com/p/cryptsetup/issues/detail?id=7