(Denny Crane: "I Don't Want To Socialize With A Pinko Liberal Democrat Commie. Say What You Like About Republicans. We Stick To Our Convictions. Even When We Know We're Dead Wrong.")
I recovered many DVDs from my home after the Katrina flood. 70% were outright unplayable. 10% could have been playable, but the security code was damaged and the player asked for the code to unlock the disc. You could see the files there, just not play the movie. The other 20% played just fine.
All the ones that played were from MGM studios. Others like Disney and WB studios DVDs were trashed. It all had to do with the quality of the DVD and I was surpised that the difference fell so sharply along production company lines.
On the other hand, 95% of my CDs played. The 5% I lost were from local studios that used cheap CDs.
All my personally burned DVDs and CDs were lost even though I always used high quality materials (or so I thought).