Last month a user encountered a problem with Decorate throwing a TypeError because the interpolated footer was a unicode where it was expected to be a string. See the thread at http://mail.python.org/pipermail/mailman-users/2008-October/063786.html.
It turns out that he was interpolating user_address in the footer and some of his member addresses are unicode causing the interpolated footer to be unicode.
I note that since 2.1.3 (before my time) bin/list_members has had a --unicode option to list unicode members. I can't see in current Mailman how a member address can be unicode.
Are unicode addresses expected? Under what circumstances? Was this a bug at one time?
My main concern is I worked up a patch http://mail.python.org/pipermail/mailman-users/attachments/20081028/76521ff4/attachment-0001.txt to fix the TypeError for the user with the problem, and I wonder if it should be committed in the current code.