DOCBOOK: Problems generating a html book using XSL and Saxon

[Gary Stewart <gis@staffmail.ed.ac.uk>]

I'm having difficulty generating a HTML book using Saxon7 and the XSL
version of docbook (1.57.0).

The book is fairly trival:

<?xml version="1.0"?>

<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
          "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd";>
<book>
<title>Brains - Zombie Food</title>
<chapter><title>Munching</title>
<para>
Brains taste nice.
</para>
</chapter>
</book>

but result in the error:

Error at xsl:element on line 69 of file:/O:/xml/docbook/html/autotoc.xsl:
  Namespace prefix  has not been declared
Transformation failed: Run-time errors were reported

I also get warnings "Using original entity definition for " on &inodot;,
&lt;, &gt;, &amp;, &quote;, &apos;

Articles generate okay (so I assume that it is the something to do with
generating a table of contents that is going wrong), and the fo file
generates okay.

Any ideas?

Thanks,

Gary