I use DVD Shrink and when I want to resize the movie I just use the RE-Author and drag the main movie over and that cuts out and takes care of the previews and shortens the movie alot. I have noticed on a couple movies like Madigascar after trying to do it, I find that it has disabled Shrink in a way that the DVD tray will not pop out after doing it, what is it ? DVD Shrink has to be reinstalled to work again.
The new copy protects have is your problem, since DVD shrink is no longer updated, it can't handle madegascar.You will need an alternate source of copy protection removal such as DVD Fab Decrypter, AnyDVD, DVD43 but in conjuction with AnyDVD. Remove the copy protect and Shrink should work fine.