Hi! In KeywordIndex the newKeywords get called if they are "callable": def _get_object_keywords(self,obj): newKeywords = getattr(obj, self.id, ()) if callable(newKeywords): # (*) newKeywords = newKeywords() if hasattr(newKeywords,'capitalize'): # is it string-like ? newKeywords = (newKeywords, ) return newKeywords This fails if the newKeywords are stored in a PersistentList. Callable is true, but there is no __call__ attribute. I changed the line marked with (*) to if hasattr(newKeyword, "__call__"): and this seems to work I think this does not break anything and could be included in the original. Am I the first how uses PersistentList for an indexed attribute? Is there a reason not to do so? thomas Please CC to me I am not on the list yet -- Thomas Guettler <guettli@thomas-guettler.de> http://www.thomas-guettler.de