AFAIK, it was possible to identify MZ-S bodies that are affected by entering Serial # at the following URL on Pentax Homepage:
http://www.pentax.co.jp/japan/news/information/20010619-s.html
I did try it two years ago when I bought MZ-S. Return info was that my MZ-S is clear. The unfortunate part of this is that, obviously, page is not available anymore. So this won't help you much, I'm afraid. Maybe somebody can still find out the corresponding page somewhere else on Pentax pages.
Matja�
It looks like this link will do the job.
http://www.pentax.co.jp/japan/news/information/20010619-s.bak
Andre
