The Seventh Seal (June 2009)
Pierrot le fou (September 2009)
Paris, Texas (January 2010)
Howards End (February 2010)
Summer Hours (April 2010)
M (May 2010)
Walkabout (May 2010)
See also this post from Blu-ray.com for a list of less commonly problematic titles or here for a more comprehensive listing of potentially affected discs.
Even if these discs played fine when you purchased them, you might want to check them again and see if any issues have developed. Don't just check the color of the disc though. Fast forward through the features and extras to see if the disc freezes up at any point. Make note of specific problems with any affected discs, and email your findings to firstname.lastname@example.org. Please be patient in awaiting a response, as they are getting a lot of emails about this.
Criterion has been responding to individual emails about this matter as follows:
See also this more detailed response.I hope this email finds you well. Thank you for writing in regarding a discoloration and playability problem with one or more of your Criterion discs. We are aware of this issue, which appears to affect a number of titles pressed four or five years ago at a pressing plant that we no longer use, and we are currently working on a solution. Please be assured that we are dedicated to your satisfaction and will be replacing defective discs. As soon as we have a system in place to handle exchanges efficiently, we will send out a link with instructions on how to receive replacement discs. Thank you for your patience and understanding while we work through this issue.
All the best and thanks for supporting Criterion!