There's a burning smell that comes out from the whitebook that I have after some usage. The smell gets stronger when I try to play video from a dvd. Does anyone encounter this problem?
Is your MacBook new? When they're new, they give out a smell that may be construed to be a burning smell.
However, if your MacBook is not new and like you said, it gets worse when running a DVD, then you might have something broken inside the player that causes the smell from friction inside the SuperDrive. I would call AppleCare and get it checked out. Make the best of your 1 year warranty (or 3 year AppleCare warranty if you bought it.)
Good Luck!