Another data point fwiw - Fairmount, on Mac OS X, which does the same job but uses VLC for its backend (it basically presents the decrypted disc as a mounted volume) - rips the same DVD with no problems.
Another data point fwiw - Fairmount, on Mac OS X, which does the same job but uses VLC for its backend (it basically presents the decrypted disc as a mounted volume) - rips the same DVD with no problems.