I've been trying to play a DVD on my computer and when I start it, the FBI Warning, Attention screen, and DVD rating play, but once the menu comes up the screen gets all glitchy and the sound gets all distorted. This happened once and I came to the conclusion I needed a DVD Decoder, but now that I have one, this other DVD won't play. I can play another DVD in my computer just fine, and it's not the DVD because it plays on my DVD player hooked up to my family room TV. Anyone have any suggestions to what might make it play correctly?