If it is getting to 20% every time and then stopping in the same place then you
probably have a bad spot on the disc maybe a very small scratch or a small pit
in the disc surface. I'm just wondering here but have you tried cleaning the disc
going from the center out to the edge and not going around the track on the disc?
Take a very, very, very, close look at the disc and use a magnifying glass if you
happen to have one lying around and see if you can see any micro scratches or a
small spot in the disc surface if so then that is more than likely what is causing
you the problem because DVDFab should be able to do that disc with no problem.