DVDs Burn Properly, But files are corrupt

This has been going on for a while now and Im on the verge of killing the assholes that made my supposedly good DVDRW drive. At first it worked just find and I had no errors. Lately its been fucking up.

I use Nero 6 and burn the DVD.
No Errors, Even when it Verifys the data.
After the burn when I check the DVD I find that several of the files are unreadable.

Note: I am burning Avi Files. The original files on my HD are perfectly fine. I've burned many DVDs like these before, using the same Drive and Software without having any problems. Same DVD+RW discs too. I also uninstalled Nero 6, and installed Nero 7... same problem.

This problem is really ticking me off and if anyone can help, I'll be forever in your debt.

Did you update Nero when the problem started?  I used to hear things about them detecting pirated keys and burning bad discs instead of locking you out. ^^