[Zope] CatalogAware, external method manage_afterAdd

Hi, I'm once again trying to get further in my test products. * I've created a catalogAware ZClass, called KBItem * KBItem contains an external method with id manage_afterAdd Now, I can add KBItem instances in Zope without problems, BUT! when having a ZCatalog inside a folder with the id Catalog and then try to create a KBItem instance, I get following error (where testje is the id of the KBItem I try to create) : Zope has encountered an error while publishing this resource. Error Type: ValueError Error Value: Uncatalog of absent id 'TEST_Folder/testje' Help! I don't know what I'm doing wrong or what is happening! What does it mean and what can I do? Thanks in advance, Tom.