[Zope] Can't add a ZClass with constructor object

[Vital Lobachevsky]

Hi, all

(Zope 2.6.1 (binary release, python 2.1, linux2-x86), python 2.1.3, linux2)

I can't add a ZClass with constructor object:

Error Type: KeyError
Error Value: title

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 Products.PlugIns.PlugIns, line 846, in manage_addZClass
KeyError: title

I asked Google about this error. But didn't find how to fix it. Any help will 
be appreciated.

TIA
-- 
-tick