Hi, If you try 'Test'ing the conent_type_registry with only, say, the 'file name' field filled in, you get a ValueError from ContentTypeRegistry.__call__ because it tries to split an empty field: major, minor = SLASH_SPLIT.split( typ ) I guess default values need to be supplied in the function. cheers, seb -- [] j a m k i t seb bacon T: 020 7749 7218 F: 020 7739 8683 M: 07968 301 336 W: www.jamkit.com