[Zope] How to set Proxy-Roles

Hi, i have a DTML-Method that adds a subfolder to a folder. I want to give anonymous users the permission, to add a Folder by using this DTML-Method. I added the Proxy-Role "Manager" to this DTML-Method, but anonymous users still can't use it - everytime they get a "You are not authorized to access manage_addFolder". Where is my mistake? Thanks Robert