First of all, I haven't tried this yet, because I don't have enough spare DVD-Rs lying around. Here Goes...
1. Download DVDBackup for OS X - with this, you can copy the stuff to your HD, and get rid of all the Copy protection.
2. If it ends up less than 4.7 GB, burn it onto a DVD using the same directory structure as the original.
3. For better info, try going to The Mac DVD Resource
Good Luck! Lemme know if this works!