How much compression are you having to use in Shrink? This shouldn't cause a complete stop in play, but extreme levels of compression with Shrink can cause problems sometimes. Normally it shows up as compression artifacts and blockiness.
I only have two things left to try and both are very long shots. First, increase burning speed to 6x if it is an option, 8x if not.
And second, try running the movie through FixVTS after decryption in DVDFab and just before compressing with Shrink. This step probably won't do anything but it is one of the few things left I can think of to try. It is much more likely that you are looking at a problem in the player than a structural problem in the dvd-video itself. http://www.videohelp.com/tools/FixVTS
Take one of the disks that stops playing and try it in a dvd player of a friend. See if it has problems in the same section of the movie.