I have an issue with my menu which is pieced together inside XSLT using apply templates.  The menu is a simple list of horizontal tabs, the submenus (if there are any) slide out on hover using Jquery.

If the current page is any First (Home) or 2nd level content page  (About Us, Products, Newsletters, Contact Us), the menu works correctly.  If I am on the 3rd level, the sliding menu (3rd level) are non-existent.  Any advice on why it isn't working as expected would be much appreciated! 

I am also fairly sure there are more succinct ways of achieving what I want, so any advice on how to re-work it optimally would also be mcuh appreciated.

My basic content structure is (as advised by this post http://www.blogfodder.co.uk/2010/5/13/building-your-first-umbraco-site-from-scratch)

Home
- About Us
- Products
---- Product 1
---- Product 2
- Newsletters
---- Newsletter 1
---- Newsletter 2
- Contact Us

My XSLT is

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE xsl:stylesheet [ <!ENTITY nbsp "&#x00A0;"> ]>
<xsl:stylesheet 
  version="1.0" 
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform" 
  xmlns:msxml="urn:schemas-microsoft-com:xslt" 
  xmlns:umbraco.library="urn:umbraco.library" xmlns:Exslt.ExsltCommon="urn:Exslt.ExsltCommon" xmlns:Exslt.ExsltDatesAndTimes="urn:Exslt.ExsltDatesAndTimes" xmlns:Exslt.ExsltMath="urn:Exslt.ExsltMath" xmlns:Exslt.ExsltRegularExpressions="urn:Exslt.ExsltRegularExpressions" xmlns:Exslt.ExsltStrings="urn:Exslt.ExsltStrings" xmlns:Exslt.ExsltSets="urn:Exslt.ExsltSets" xmlns:umbraco.contour="urn:umbraco.contour" 
  exclude-result-prefixes="msxml umbraco.library Exslt.ExsltCommon Exslt.ExsltDatesAndTimes Exslt.ExsltMath Exslt.ExsltRegularExpressions Exslt.ExsltStrings Exslt.ExsltSets umbraco.contour ">


<xsl:output method="xml" omit-xml-declaration="yes" />

<xsl:param name="currentPage"/>
<xsl:variable name="siteRoot" select="$currentPage/ancestor-or-self::root/*[@isDoc and @level=1]" />
    
<xsl:template match="/">
  
  <ul id="nav">
    
    <!-- Run for rootnode and 2nd level nodes (will deal with 3rd level inside the template match)-->
    <xsl:apply-templates select="$siteRoot [@isDoc]" />
    <xsl:apply-templates select="$siteRoot/* [@isDoc and string(umbracoNaviHide) != '1']" />
    
  </ul>

</xsl:template>
    
<!-- HOMEPAGE (matches as its the only one at level 1)-->
<xsl:template match="*[@isDoc]">
  <li>
    <a href="{umbraco.library:NiceUrl(@id)}">
      <xsl:value-of select="@nodeName" />
    </a>
  </li>
</xsl:template>

<!-- SECOND LEVEL PAGES (matches all at level 2)-->
<xsl:template match="*[@isDoc and @level = 2]">
  <li>
     <!-- if this node has a child then -->
     <xsl:if test="*[@isDoc and string(umbracoNaviHide) != '1']">
       <xsl:attribute name="class">trigger</xsl:attribute>
     </xsl:if>
     <a href="{umbraco.library:NiceUrl(@id)}">
       <xsl:value-of select="@nodeName" />
     </a>
    
     <!-- if this node has a child then (selects 3rd level nodes) -->
     <xsl:if test="*[@isDoc]">
        <ul class="submenu">
                <xsl:apply-templates select="*[@isDoc]" />
        </ul>
      </xsl:if>            
  </li>
</xsl:template>

<!-- THIRD LEVEL PAGES (matches all at level 3)-->
<xsl:template match="*[@isDoc and @level = 3 and string(umbracoNaviHide) != '1']">
  <li>
    <a href="{umbraco.library:NiceUrl(@id)}">
            <xsl:value-of select="@nodeName" />
    </a>
  </li>
</xsl:template>

</xsl:stylesheet>

Thanks!