Hi, I have a question about ZPatterns:Rack. I got 10 items in a Rack and I want to remove those objects. By reading Rack.py , I know that manage_pack can do this for me if getItem(key) return None for those objects. Well, how to return None? One way I found is that: under "Storage" manage_tab, there is a option: {Objects are: loaded by accessing attribute [xxxxx]} assign xxxxx to be a "non-existing method", ie, any string except those attributes' names. Then, by clicking "remove orphaned slot" which triggers manage_pack. I can see the counter of "Persistent slot in use" was reduced. The question is that: why it reduced gradually? It doesn't reduce to 0 by just one click. I have to click it several times in order to remove all of them. How does it happens? What's the right way to remove an item from a Rack? Thanks a lot. Iap,Singuan