[Zope] aquisition problems with subitem in pyhton product

hello i've two python products which subclasses Folder.Folder One is called "Site" The other "Topic" there is a index_html attribute in the Site Product code: index_html = (DTMLFile('dtml/representation/site_index_html', globals())) now i put a Topic product into a Site product the Topic product itself has no index_html if i now request the url /theSite/theTopic/index_html the index_html shows up, but with the attributes of the Site object (like <dtml-var absolute_url> == /theSite) so its the same as: /theSite/index_html it appears that i've got the same problem with other methods please help thanks in advance