[Zope] getting a folderish zclass to automatically add things to itself

I've been hammering my head against this - I'm trying to get a folderish ZClass to add a couple of instances of a different ZClass to itself when it's created. I've looked at Kevin's ZClass How-to (the bit at the bottom of it needs a <pre>, btw) and I've tried various versions of trying to call the createInObjectManager inside the _add page of the ZClass... These all result in creating the object in the parent folder of the new folderish object. I know I'm missing something really really stupid. Can someone help me here? Anthony