[Zope-CMF] Other way to add portal content that invokeFactory ?

[Gitte Wange]

Hello,

I need to add an object in the root of my CMF site ... but I can get 
invokeFactory to work (restrictedTraverse on portal_url gives an error).
So I was wondering if there was another way to create an object in the root 
of the CMF site ?

TIA,
Gitte Wange