[Zope] ZClass proxy roles - don't work?

I have a Product that contains several nested ZClasses. I'm trying to allow an anonymous user (actually a Xron object) to call a method on an inner class that will modify some object attributes. I have given the method a proxy role of Manager, but calling it still raises a login prompt. If I don't log in, I get 'not authorized to manage_changeProperties'. Any advice appreciated. (Anticipating one form of advice; yes, I really wish I had written the thing as a Python Product, and I'm trying to rewrite it properly in my Copious Free Time, and I'm never going to put a ZClass in production again.) Thanks -- Wade Leftwich Ithaca, NY