mac superdrive not recognizing dvd movies

I have tried several different movie DVDs but none of them work. It shows them on the desktop but when I try to use quicktime or VLC it just hangs or it shows nothing. I have tried other DVDs and a CD and those work fine.

I have a fall 2011 MBP 15in

Thanks,
Sims

Which region are you in and what region are the DVDs recorded for? (assuming they're originals and not copies)

The US and the DVDs were bought in the US. They work on other devices.

OK, just wanted to make sure they weren't recorded for another region. Since other DVDs and CDs seem to play OK, the drive itself must be alright. Are the movies regularly recorded or are they Blue Ray? I know when I buy a commercial recorded movie I sometimes accidentally pick up the Blue Ray version. Blue Rays can not be played on a Mac.

no I'm absolutely positive that these are not blu-ray discs. Could it be possible that I have software that I have on my mac that could be jacking it up? I guess I can't imagine that would prohibit me from not watching movies...