[Zope] Overriding manage_properties in a ZClass

I have a ZClass where I want to use my own manage_properties dtml page. However, when I use manage_properties = DTMLFile('www/manage_editForm', globals()) and then manage_options=( {'label':'Properties', 'action':'manage_properties'} , ... ) The instance (which is derived from Folder) merely shows the standard Folder properties (e.g., title only). changing the 'action':'manage_editForm' doesn't work either. Hints, anyone? TIA, Ron