Nox, onehundred, thanks for responding.

Needswings, thanks for the photos. Have you experienced the same problem, prompting you to buy new pre-painted strips? One spot on mine has now gone past the primer, down to what looks like a galvanized finish. I guess a galvanized finish would make sense if M-B has determined that this part is particularly succeptable to trapped moisture corrosion. But it is also fairly difficult to keep paint adhering to zinc. I only have the problem in one of my strips, but will the other one eventually chip also?? Hmm. If you would, please leave a post after you do the replacement, and let me know if it is possible to remove the strip without destroying it. Thanks.