Matthew Wilbert writes:

I am getting an access error I don't understand at all, .... <dtml-in "ZopeFind(this())"> <dtml-var sequence-item> .... Zope Error Zope has encountered an error while publishing this resource. Unauthorized<

You are not authorized to access title_or_id.

What Zope version do you use. You need at least Zope 2.2.2 as there was a bug in earlier Zope versions. This bug may present itself exactly as you described. Dieter