not if it has been authored properly. the things that stop people usually are bad media, bad quality or scratched original, bad sectors in newer dvds (dvd decrypter rips these no probs), drives running in pio mode, compatability problems (uninstall roxio and incd), fat32 hard drives (cant handle 4+gb sizes). If you have the latest firmware for your drive, use good media and originals, and follow the guides you cant go wrong. When a company brings out new encryption, it takes about a week for someone to break it....if it can be read it can be burnt
I backed up troy without any drama. There is no commercially available movie that cannot be backed up. Whether you need new software/new original depends on the movie. Its not rocket science so keep it simple, lots of ppl come unstuck because they try to use 5 different programs at once. DVD Shrink, DVD Decrypter is really all you need for basic movie backups and its free. Graduate to nero for fancier features but remember to keep it simple