Hi I am trying to get a handle on how I should handle peristence in my python products. I have read all the ZODB documents and all the Product tutorials, which all led me to believe that 1) mutable objects such as lists and dictionaries are not persistent and that updates to these will not be implicitly saved into the ZODB, and 2) that custom classes would certainly not persist. That all seemed fine, and I used persitent mapping and __setstate__ to fill things back in where necessary. But then I decided to demonstrate that persitence does break as suggested. I used boring product, added a dicitonary and a custom class that contains it's own dictionary.... let the user update name : value pairs for both, and print the contents through index.dtml The problem is that everything persists fine !!!! through restarts, everything? Why does it work??? shouldn't it not? I have attached the modified boring product .... boringplus ..... it's dead simple to follow if you have made products before. Any explanation would be really nice. regards Matt