I tried to watch a DVD on my computer last night and the DVD showed up as being a blank DVD, it even made the window pop up asking what I wanted to use for the DVD like burn a cd or whatever... I stuck it in our DVD player and it played just fine. I've never had a problem like this before, I've been able to watch all DVDs on my computer so far. This is a really old DVD that I just got from 1991 I think, could that be a problem???