[Zope] CatalogAware does not work?

[Milos Prudek]

I followed Automatic Cataloging example in Zope Book, Chapter 9.

Everything works fine except automatic cataloging of newly created
fields ("author", "content"). When I change data in those  fields it is
not reflected in the catalog. 

When I add a new instance, it is not included in the catalog. 

This can be verified by clicking on the Catalog tab, and choosing the
newly added instance (the page that says "the goal of this page is to
provide basic debugging information about what is in the Catalog on a
specific object."). 

Also, calling <dtml-in>Catalog</dtml-in> does not display new/modified
data.

The situation can be rectified by manually clicking Advanced/Update
Catalog (for modified fields) or by Find Objects (for new instances). In
other words, the catalog can only be updated manually.

Strangely, the "date" field does not suffer this problem.

I run Zope 2.3.1 source release. I use the latest Zope Book, dated March
13, 2001

Is the Zope Book text about Automatic Cataloging valid? What mistake I
make?

--
Milos Prudek