[Zope] CalendarTag error

[Gitte Wange]

Hello

I have this calendar in my CMF site. And it has worked so far untill we 
upgraded our Zope.

The error is this:

Zope Error
Zope has encountered an error while publishing this resource.

Error Type: NameError
Error Value: global name 'expr_globals' is not defined

Looking into the code for the CalendarTag I see there is a variable named 
expr_globals. It is passed as an argument to an Eval function.

Now ... I guess it worked before because we were using and older python 
version. Anyone who knows how to get this to work with python 2.1 ??

Thanks,
Gitte Wange