It's impossible to use a forum to judge how widespread a problem really is, but in the past, forum posts have lead to product recalls. If you check your Blu-ray titles now and find that the data side seems to be showing signs of rot (picture below), you should seek a refund or replacement disc immediately.
Here is an image posted by the user Venom5 on AVS Forum...
Sources:
Engadget HD
AVS Forum
Written by: James Delahunty @ 16 Jun 2007 17:45