Hallo, I'got a fundamental question: Why should you switch from the built-in authentication mechanism to a product like GUF or Login-manager??

You can choose the storage for your userdata yourself, which may be practical for i.e. - huge user base and/or you also like to store adresses etc. easily. - adding/changing users through mechanism outside of zope - verifying users through mechanism outside of zope (ie. apache's various mod_auth_*) for tasks outside of zope (try to stream a .rm-file only to built-in authenticated users) cheers. oliver