This sounds like the promise of a really capable medium, which is to say the thread of non-standardization.
They can make DVDs that don't give you much control. The Academy (for your consideration) copies of Cast Away would only play start to finish. Pause, Scan or Skip took the movie back the FBI warning.
Now add this Java thing, that DVD creators are probably not thinking about in terms of what it will do to your ability to use the disc as you're used to using a DVD.
A good answer is easier with a clear question giving the make and model of everything. "The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw