DVDDecrypter has been outdated for a while now as a decryption/ripping program. It still works for the majority of titles, but newer protection schemes are beyond its abilities to rip properly. If you are looking for a free replacement, the only option now is DVDFab HD Decrypter. http://www.dvdfab.com/free.htm
Be aware that as you use the free section of this program you are using up the 30 day trial of the complete program. After that trial is up, the free decrypter/ripper will still work, but the advanced options will not.
Another option is to buy AnyDVD. It works in the background and you can use DVDDecrypter in conjuction with it if you like. Or use the built-in ripper. It is still being updated, and is very effective.