New copy protection schemes are introduced all the time for dvd movies. Many of the poor decryption programs lag far behind in solving these copy protections, so you run into a fair number that are beyond their capabilities, at least until they update the program again.
AnyDVD and DVDFab are updated quite often. I've seen several updates for AnyDVD in the course of a couple of days. Other programs, like yours, often lag behind by months.
It sounds like your program is not only a decrypter, but a conversion program, since it can produce videos for your Itouch. You might want to get the trial for AnyDVD and rip the entire movie to the hard drive with its built-in ripping function. Then work with the movie off the hard drive using your current program to convert to the format used in your device.
I don't know if your program will work with AnyDVD in the background or not...some have problems with that. You'd just have to test it, or turn off AnyDVD when you start it.
The trial for AnyDVD is for 21 days. It won't hurt anything to try it. www.slysoft.com