Are you doing things? You shouldnt be doing much, if anything, while you are burning a DVD. Remember when CD BUrners first came out? You couldnt do ANYTHING, not even play Solitare when burning a CD! The same goes with burning a dvd, somewhat. You can still do stuff, but not much. It still needs most of your specs to do stuff.
Are you burning from a file, or a direct copy of a dvd?