How to customize a template from division.xsl?

I'm trying to customize the book template from the dvision.xls stylesheet and run into an error for xsltproc. At this point, I'm not even changing the template, but simply putting a copy of it in my customization file produces the error, "I/O error : Is a directory" (happens when chunking the index.html file).

<xsl:template match="book">

  <xsl:call-template name="id.warning"/>

  <div>

    <xsl:apply-templates select="." mode="common.html.attributes"/>

    <xsl:call-template name="id.attribute">

      <xsl:with-param name="conditional" select="0"/>

    </xsl:call-template>

    <xsl:call-template name="book.titlepage"/>

    <xsl:apply-templates select="dedication" mode="dedication"/>

    <xsl:apply-templates select="acknowledgements" mode="acknowledgements"/>

    <xsl:variable name="toc.params">

      <xsl:call-template name="find.path.params">

        <xsl:with-param name="table" select="normalize-space($generate.toc)"/>

      </xsl:call-template>

    </xsl:variable>

    <xsl:call-template name="make.lots">

      <xsl:with-param name="toc.params" select="$toc.params"/>

      <xsl:with-param name="toc">

        <xsl:call-template name="division.toc">

          <xsl:with-param name="toc.title.p" select="contains($toc.params, 'title')"/>

        </xsl:call-template>

      </xsl:with-param>

    </xsl:call-template>

    <xsl:apply-templates/>

  </div>

</xsl:template>

Is this likely a problem with precedence? If so, any idea what I need to do to be able to include this template in my customization layer?

BTW, I'm using the 1.78.1 stylesheets.

Thanks,

Ken