One big problem I had migrating to Linux was a way to truly rip a DVD.. often with deliberate bad sectors. I wrote a script that will repeatedly call dd and build up a .iso a bit at a time, hopefully avoiding the bad blocks and replacing them with zeros in the resulting .iso. It's a little raw at this point, but any help updating it is appreciated. In order to make it work correctly you'll need to change a couple variables at the beginning of the script (the number of blocks, and the input device).