[Zope] zcatalog strange behavior

Hi every one I've used zcatalog 2 years ago. Every thing was perfect My zclass objects where removed from zcatalog when they were delete etc ... Today i try to create another zclass on the same zope server (2.6) zclass with zobject,zcatalogaware inheritance and the zcatalogawareness don't work any more. And I don't know why !!!!!! So each time a property is modified i should force a refresh like that : my_zcatalog.update(refresh=1) this refresh all my indexes. But it's not normal On the other zclass product, each time an object is modified indexes are modified transparently How can i check,debug, test Zcatalog-Aware ability ? Thank's for all