If you had one of the new protection schemes on this dvd, then yes, DVDDecrypter would have failed to decrypt and rip the movie to the hard drive. So it seems you are safe with this particular movie.
DVDDecrypter hasn’t been updated in a couple of years at least, so it will fail on its own with some newer movies. Using it in conjunction with AnyDVD works very well for the most part. AnyDVD is constantly being updated, but as I said, it is not a free program. You can download the trial and use it for 21 days to see if you like it.
DVDFab HD Decrypter is also updated, just not quite as quickly. Very nice to have options when decrypting dvds, so I recommend having it around, even if you choose to buy AnyDVD.
You might also want to look into a couple of other programs. DVDShrink and DVDRebuilder. They will let you remove extras, and reduce the size of a commercially made dvd to fit onto a single layer dvdr. I use DVDShrink on movies that don’t need much compression. DVDRebuilder will reencode the movie, and produce very high quality results on movies that require more compression.
You can find DVDShrink at www.mrbass.org, and there are a number of guides there for its use. DVDRebuilder can be found here: http://www.jdobbs.com/