One factor that may be hampering Apple's ability to identify and track such manufacturing and/or production problems is that international AppleCare complaints aren't tracked on analyzed in a central database. Instead it's a patchwork of databases kept by individual countries that isn't shared amongst the group. This renders Apple unable to detect worldwide complaint patterns that would alert them to defects.
Read more about the complaints and censorship and decide for yourself.
Update: A Web site was posted yesterday with uncensored discussion of this problem and loaded with specific, up-to-date advice on what people can do if they have this defect.