Is there a way to test commercial DVDs for errors?

[dooks]

Is there a way to test commercial DVDs for errors before watching them? I've recently rented some movies from blockbuster online. A few of them I've received had problems partway into the movie that made them unwatchable. Both of my DVD players, a Denon and a Philips, had problems in the same spot. I ended up sending them back and having them send me another copy. It would be nice to have a way to test them before I start watching them so I don't end up watching the movie over a period of a few days. Does anyone know of some software that can test them?

[lordsmurf]

Nero CD-DVD Speed, do a scandisc

It's the same as testing burned discs.
http://www.digitalfaq.com/media/burnquality.htm

[dooks]

Using Nero CD-DVD Speed works great. I haven't run into any more DVD problems, but a CD I bought from Amazon kept skipping on one song. I tested the CD and it found some bad spots. Amazon sent me a replacement and I sent the bad one back.