You can always e-mail Oppo; they're very good at answering any questions promptly. I'd wager they'll say the same thing about the 983 that they told me about the 981 -- that the resolution of DivX files is so low that any benefits of upconversion will not neccesarily be noticeable. Yes, it's not really answering the question, but that's what they told me.
cheers,
supervij