Hi all, I'm trying to create a Folder-ish ZClass that has certain attributes which are actually linked to data that lives in a SQL database. I know I could just use methods to access the data, but I'm trying to gain some ZPatterns foo, and it seems to me that I should be able to get this data to be exposed exactly as though it were just a regular attribute on a PropertySheet. I'm having a hard time finding the magic combination, though... As I understand ZPatterns, these folder objects should be DataSkins, with DataManagers that would fetch and store the data where appropriate. However, if I try to create a ZClass with both OFS:Folder and ZPatterns:DataSkin as base classes, whenever I try to add it somewhere I get a Key Error for "_v_dm_". Can anyone help me discover the "right" way to use ZPatterns to make a persistent Object File System type of object transparently mingle attributes from PropertySheets, SQL Methods, etc.? I know that I'm close... I just can't quite wrap my head around it... Thanks, -r