Here is my try: In the Apple Object, I have the following method defined: def get_apple_type(self): typelist = ['No apple types defined'] for parentObj in self.aq_chain: try: typelist = parentObj.typelist return typelist except: continue return typelist I then do the following when I create the object: a = Apple.Apple(thisID) self._setObject(thisID, a) a = self._getOb(thisID) # Now try to set the typelist property PropertyManager.manage_addProperty(a, 'apple_type', a.get_apple_type, 'select', None) I can refresh the product fine, but when I try to add an apple, I get the following error: *Error Type: UnpickleableError* *Error Value: Cannot pickle objects * The traceback is as follows: ** Traceback (innermost last): File C:\lib\ZopeDev\lib\python\ZPublisher\Publish.py, line 150, in publish_module File C:\lib\ZopeDev\lib\python\ZPublisher\Publish.py, line 114, in publish File C:\lib\ZopeDev\lib\python\Zope\__init__.py, line 159, in zpublisher_exception_hook File C:\lib\ZopeDev\lib\python\ZPublisher\Publish.py, line 102, in publish File C:\lib\ZopeDev\lib\python\Zope\__init__.py, line 173, in commit File C:\lib\ZopeDev\lib\python\ZODB\Transaction.py, line 234, in commit File C:\lib\ZopeDev\lib\python\ZODB\Connection.py, line 346, in commit (Info: (('Products.OrchardManager.AppleInfo', 'Apple'), '\x00\x00\x00\x00\x00\x00#\xa8', '')) UnpickleableError: (see above) Any help? Thanks, VanL * * * *