Problem viewing DVDs on my computer

[holeplug]

I have a problem viewing the picture clearly when I try to play DVDs on my computer. The audio works just fine and is in sync with the video. The video actually plays and I can view it but the picture is alittle fuzzy. I thought/think that it is some kind of codec problem so I reinstalled the mpeg-2 codec but I still get the same problem. I can view other video types just fine it only ever happens when I want to watch a DVD.