Interesting thread on further titles suffering from rot; http://www.avsforum.com/forum/150-blu-ray-software/857067-blu-ray-disc-rot-few-titles.html Page 10 is interesting as an employee of Sony stated some kind of impurity with the construction on certain discs.
I think a lot of problems have to do with how people store things too. I read that VHS tapes are supposed to be stored up right vertically not flat. Also that they are supposed to be played every so often. Consistent temperature is probably the most important though for VHS, Laserdisc, DVD, Blu-ray or any other important item. If you live in a seasonal area make sure you aren't storing this stuff against an exterior wall which will be subject to up and down temperature changes.
