[Zope] ZClasses, nesting, and properties

Note: My list subscription has fallen over and died, so please respond to me as well as to the list. Thank you. I have a ZClass with a property sheet called 'info'. On this sheet is a text property 'contents'. The ZClass descends from Folder and Catalog Aware. When I place an instance within an instance, and in a dtml document acquired from above both instances call '<dtml-var contents>' I get the contents property of the outermost instance. Why is this happening, and how can I avoid it? Please help!