Identify first <section>?

I hope someone can help. I don't seem to be able to identify whether my 
<section> is the first child of <chapter> or not...

Docbook document is of the form:

<book>
  <chapter>
    <chapterinfo>...</>
    <section role="L1">...</>
      <section role="L2">...</>
    <section role="L1">...</>
  </chapter>
</book>

When the FO stylesheet finds the first <section> within a <chapter> (ie. 
line 4 above), I want to force a new odd page. I'm trying to do this using 
a method outlined in:
http://lists.oasis-open.org/archives/docbook/200211/msg00135.html

In my compiled titlepage specification file I have:

<t:titlepage t:element="section" t:wrapper="fo:block">
...
  <t:titlepage-before side="recto">
    <xsl:param name="node" select="."/>
    <xsl:if test="not(node/preceding-sibling::section)">
      <fo:block break-before="page"/>
      <fo:block font-size="14pt" font-family="verdana" 
font-color="red">DEBUG:</fo:block>
    </xsl:if>
  </t:titlepage-before>

The <xsl:if test="not(node/preceding-sibling::section)"> doesn't seem to 
pick up what I'm after. Any suggestions?

Mart