Have you tried them on a stand alone DVD player yet? That seems like the logical next step in troubleshooting, y'know, making sure that they weren't from a bad batch of disks at the factory. Yeah, I know. It's three seperate sets from at least two different vendors (you didn't say whether or not the replacement set was from the same seller on Amazon). But there's still a small chance that it could just be bad disks anyway.