[Zope] container has no security assertions ?!?!

When I try to access the mime type of an uploaded file .... <dtml-boundary type_expr="CVfile.headers.headers[1]" name_expr="CVfile.filename()" disposition=attachment encode=base64> I get this exception... An exception occurred in a DTML method or document. Error type: Unauthorized Error value: Access denied for ['Content-Disposition: form-data; name="CVfile:file"; filename="D:\\Arrivals\\Glossary.doc"\015\012', 'Content-Type: application/msword\015\012'] because its container, <rfc822.Message instance at 20112e0>, has no security assertions. What does this mean? What am I doing wrong? -- Thanks -- Loren