So to be able to backup your DVD movies you need a third party program that "unlocks" the DVD's security features.
A very well known program is AnyDVD. I have been using that for about 5 years.
Also, their "CloneDVD Mobile" makes perfect PocketPC copies of my movies and from there I can convert them using BlackBerry Video Generator or Creator.
I also use it to convert my DVD recordings from TV into AVI files that I then convert into Pearl format.
SlySoft Products | Copy Movie DVDs with AnyDVD and CloneDVD