Strange DVD Behavior When Used w/ TV Tuner Cards?

Flying_Donut asks: "Greetings! This is related to a question that popped up on Arstechnica. I, and several others are having this problem with our DVD consoles, connecting through either Hauppage TV Tuner cards, or ATI All-In-Wonder Pro cards. The problem is, that on some DVDs, we see annoying scan lines in the movies. For myself, I use BeOS Pro 5.0.3 and the All-In-Wonder Pro card, connected to an external DVD console (a Toshiba SD-2109) and the only time I see these scan lines are on Widescreen DVDS (which copmprise about 99.999% of the DVDs out there). I assumed it was some form of copy protection that the combination of BeOS and the All-In-Wonder Pro card, were seeing (sort of like old Betamax players and copy protection), but the other gentleman with the problem is using Windows (ack!) and sees the problem on some of his DVDs. Others have suggested switching from SVideo to Composite cabling, but it didn't seem to help. In any case, I wanted to tap into the Slashdot community and see what they have experienced and/or had to offer to fix this issue."