[Zope] DTML Method not working

[Ronald L. Chichester]

I took some code that was in the (work-in-progress) O'Riley book on
Zope.  In that example, then had a DTML Method used for identifying
folders and hyperlinking to them.  The code is as follows:

<ul>
<dtml-in expr="objectValues('Folder')">
 <li><a href="&dtml-absolute_url;"><dtml-var title_or_id></a><br></li>
</dtml-in>
</ul>

The problem is, it doesn't work.  I know the method is being invoked
because there is some other text that is indeed being inserted.
Moreover, there are sub-folders in the folder that calls the method.

Does anyone know what the problem is?  Is it a permission issue.  The
standard_html_header and _footer, show up just fine, along with logos
and such.  The only part that isn't showing up is the stuff that was
supposed to be generated by the <dtml-in> block.

Any hints?

Thanks in advance.

Ron
 ./.