First, try pressing the Analyse button in DVD Shrink and see if the deep analysis fixes the problem.
Then, you can try processing the Movie with VobBlanker. There is an extra PGC in madagascar and all other Ripguard titles that may be causing the problem. What I did to back up a Ripguard title was use DVD Decrypter in File mode and then Blanked out the extra PGC and extra cells in the movie with VobBlanker. I also blanked out the extra garbage and all those FBI Warnings and Interpol crap.
After that DVD Shrink had no problems and the movie did not have to compress to fit on a DVD5.
About AnyDVD. This is not free. It costs $30, but there are discounts available from time to time. It is not like Decrypter because it does not do any ripping. What it does is remove copy protection on the fly. It does this while running in the background. Just look for the Red Fox on your system tray. You can then simply drag and drop a movie to your HD, or rip with your favorite ripper. It is a great program and updated within minutes if an update is needed.
If you do not want to spend money, then look into the PSL guide, but I do not see the need for those on Current Ripguard titles. Possibly in the Future. The PSLs are good for ARccOS titles though. They take 30 seconds to make. Just follow Cynthia's guide. The first time, it may take a few minutes, but once you do it once, you will see that it is nothing but three clicks of a mouse.
There are also other (slightly more complicated) ways to get past ARccOS and Ripguard. I did it using DVD Decrypter versions that are over 3 years old. Both of these corruption schemes are nothing more than a fancy way of putting a scratch on a disc. This is not a new encryption, so a program update for Decrypter is not needed, but updates just made it easier to rip movies. A PSL is really a manual update for DVD Decrypter and a very nice feature.
After the PSL, make sure the VTS is fixed with FixVTS otherwise DVD Shrink may have compression issues. This step is as simple as dragging a VOB file on the program and pressing the "Full-DVD" button. Takes 4 seconds to do and less than 5 minutes for the PC to process the movie.