[Zope] Authentication problem with owner_info

Hello everyone, In order to diplay the person who wrote a new item I use his code : <em tal:content="here/owner_info/id">Owner</em> Unfortunatly this don't work ! I keep getting authentication problems (I test as Anonymous User). Does anybody has an idea why this is happening ? -- (°> Nicolas Évrard / ) Liège - Belgique ^^