[Zope] Overriding "title"

[Tim Moore]

I have a ZClass with a DTML method called "title" which computes a
title for an instance based on the value of another property.  Almost
everything seems to work fine...I can use the title attribute in my
standard_html_header, the computed title shows up correctly on the
management screen.  But calling title_or_id on one of these instances
raises a KeyError.  Is this expected behavior or a bug?  Zope 2.3.0 on
Linux.

thanks,
-- 
Tim Moore