[Zope] zclass propertysheets

[Danny Morgan]

OK, I've upgraded my Zope to 2.6 and it looks like the same error is 
occurring...

Problem redescription: I am trying to create a simple zclass for storing 
and presenting information about individuals. Within a product 
'sgNiceStreams' is the zclass 'sgPerson_zclass'. sgPerson has a 
propertysheet 'contactInfo' and a python script 'getInfo'.

The script has only one line:

     return(context.propertysheets.common.contactInfo.getProperty('email'))

which generates the following error and traceback:

*==============
AttributeError*

Traceback (innermost last):
  Module ZPublisher.Publish, line 98, in publish
  Module ZPublisher.mapply, line 88, in mapply
  Module ZPublisher.Publish, line 39, in call_object
  Module Shared.DC.Scripts.Bindings, line 252, in __call__
  Module Shared.DC.Scripts.Bindings, line 283, in _bindAndExec
  Module Products.PythonScripts.PythonScript, line 315, in _exec
  Module Script (Python), line 1, in test
   - <PythonScript at /Control_Panel/Products/sgNiceStreams/sgPerson_zclass/propertysheets/methods/getInfo>
   - Line 1
  Module OFS.PropertySheets, line 164, in getProperty
  Module ZClasses.Property, line 66, in v_self
AttributeError: _zclass_

===============

For whatever reason, some propertysheet information is accessible. For 
example, when 'getProperty' is changed to 'propertyMap', a mapping is 
returned.
     code:
     return(context.propertysheets.common.contactInfo.propertyMap())

     output:
     ({'id': 'fullName', 'type': 'string', 'meta': {}}, {'id': 'email', 
'type': 'string', 'meta': {}}, {'id': 'telephone', 'type': 'string', 
'meta': {}})


What is this mystery that I have spent much time on with little progress?

Danny Morgan