I do have some suggestions, but I can’t mention them here in the DVDFab forum. This subforum is for discussion of Fab products only.
By the way, you should continue to update DVDFab, as newer versions of DVDFab HD Decrypter are released on a fairly regular basis. Do you have the latest download installed?
This does sound like a problem in the structure of the decrypted movie. DVDShrink is a bit of a stickler when it comes to perfect dvd video compliance.
Edit: If you want to discuss alternatives, you should start a thread in the main main forum for copying movies: http://club.myce.com/f62/