I've never watched any DVDs on this machine, but thought I'd give it a try. I inserted a DVD video, and it doesn't seem to work. Frontrow says "The DVD cannot be played. The format is not recognized", and VLC does nothing. Except for one movie, which could be played in VLC, but still got the same error in Frontrow.
None of the movies show up in Finder. They're all region 2.
None of the movies show up in Finder. They're all region 2.