I'm spec'ing out an ecommerce site for an important group using the wicked combination of Umbraco and TeaCommerce, but I've hit a snag that I just can't figure out.  I've enabled nesting a Product Category within another Product Category (a.k.a. Sub-Category, doesn't everyone need them?), but it breaks the Navigation.xslt from the StarterKit.

Here's the result of the page load, note that everything below the first <li> doesn't get it's class populated almost as if the XSLT is "stopping" after the first <li>:

<ul id="submenu" class="lvl1">
<li class="active inpath firstitem hasChildren">
<a title="Comics &amp; Humor" class="active inpath firstitem hasChildren" href="/en/products/comics-humor.aspx">Comics &amp; Humor</a>
<ul class="lvl2"><li class="firstitem lastitem hasChildren">
<a title="New Releases" class="firstitem lastitem hasChildren" href="/en/products/comics-humor/new-releases.aspx">New Releases</a></li></ul></li>
<li><a title="Puzzles &amp; Games" href="/en/products/puzzles-games.aspx">Puzzles &amp; Games</a></li>
<li><a title="Cookbooks" href="/en/products/cookbooks.aspx">Cookbooks</a></li>
<li><a title="Home &amp; Crafts" href="/en/products/home-crafts.aspx">Home &amp; Crafts</a></li>
<li><a title="Non-fiction" href="/en/products/non-fiction.aspx">Non-fiction</a></li>
<li><a title="Keepsake &amp; Gift" href="/en/products/keepsake-gift.aspx">Keepsake &amp; Gift</a></li>
<li><a title="Children's" href="/en/products/children's.aspx">Children's</a></li>
<li class="lastitem"><a title="Calendars" class="lastitem" href="/en/products/calendars.aspx">Calendars</a></li></ul>

Here's the unmodified XSLT (every change I made failed to fix the problem):

<?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"
  exclude-result-prefixes="msxml umbraco.library Exslt.ExsltCommon Exslt.ExsltDatesAndTimes Exslt.ExsltMath Exslt.ExsltRegularExpressions Exslt.ExsltStrings Exslt.ExsltSets ">

<xsl:output method="xml" omit-xml-declaration="yes"/>
<xsl:param name="currentPage"/>
<!-- GLOBAL VARIABLES START -->
<xsl:variable name="Navigation.rootNodeId">
  <xsl:choose>
    <xsl:when test="/macro/rootPage != ''">
    <xsl:value-of select="/macro/rootPage" />
    </xsl:when>
    <xsl:otherwise>
      <xsl:value-of select="$currentPage/@id" />
    </xsl:otherwise>
  </xsl:choose>
</xsl:variable>
<xsl:variable name="Navigation.rootNode" select="umbraco.library:GetXmlNodeById($Navigation.rootNodeId)"/>
    
<xsl:variable name="Navigation.fromLevel">
  <xsl:choose>
    <xsl:when test="string(/macro/useSelfAsRoot) = '1'">
      <xsl:value-of select="number($Navigation.rootNode/@level) + 1" />
    </xsl:when>
    <xsl:otherwise>
      <xsl:choose>
        <xsl:when test="/macro/fromLevel != ''">
          <xsl:value-of select="/macro/fromLevel" />
        </xsl:when>
        <xsl:otherwise>
          <xsl:value-of select="2" />
        </xsl:otherwise>
      </xsl:choose>
    </xsl:otherwise>
  </xsl:choose>
</xsl:variable>
<xsl:variable name="Navigation.toLevel">
  <xsl:choose>
    <xsl:when test="/macro/numberOfLevels != ''">
      <xsl:value-of select="number($Navigation.fromLevel) + number(/macro/numberOfLevels) - 1" />
    </xsl:when>
    <xsl:otherwise>
      <xsl:value-of select="1000" />
    </xsl:otherwise>
  </xsl:choose>
</xsl:variable>
    
<xsl:variable name="Navigation.showOnlyCurrentPath">
  <xsl:choose>
    <xsl:when test="/macro/showOnlyCurrentPath != ''">
      <xsl:value-of select="/macro/showOnlyCurrentPath" />
    </xsl:when>
    <xsl:otherwise>
      <xsl:value-of select="0" />
    </xsl:otherwise>
  </xsl:choose>
</xsl:variable>
    
<xsl:variable name="Navigation.isSitemap">
  <xsl:choose>
    <xsl:when test="/macro/isSitemap != ''">
      <xsl:value-of select="/macro/isSitemap " />
    </xsl:when>
    <xsl:otherwise>
      <xsl:value-of select="0" />
    </xsl:otherwise>
  </xsl:choose>
</xsl:variable>
<!-- GLOBAL VARIABLES END -->
<xsl:template match="/">
  
  <xsl:call-template name="MenuItems">
    <xsl:with-param name="menuItems" select="$Navigation.rootNode/ancestor-or-self::* [@level=number($Navigation.fromLevel - 1)]/* [@isDoc and ( ( $Navigation.isSitemap != '1' and string(./umbracoNaviHide) = '0' ) or ( $Navigation.isSitemap = '1' and string(./umbracoSitemapHide) = '0' ) )]" />
    <xsl:with-param name="currentLevel" select="$Navigation.fromLevel" />
    <xsl:with-param name="levelCounter" select="1" />
  </xsl:call-template>
</xsl:template>
    
<xsl:template name="MenuItems">
  <!-- VARIABLES START -->
  <xsl:param name="menuItems"/>
  <xsl:param name="currentLevel"/>
  <xsl:param name="levelCounter"/>
  
  <xsl:variable name="count" select="count($menuItems)"/>
  <!-- VARIABLES END -->
  
  <!-- HTML START -->
  <xsl:if test="$count &gt; 0">
    <ul>
      <xsl:if test="$levelCounter = 1 and /macro/navigationId">
        <xsl:attribute name="id"><xsl:value-of select="/macro/navigationId"/></xsl:attribute>
      </xsl:if>
      <xsl:attribute name="class"><xsl:value-of select="concat('lvl', $levelCounter)"/></xsl:attribute>
      
      <xsl:for-each select="$menuItems">
        <xsl:sort select="@sortOrder" order="ascending" data-type="number"/>
        
        <xsl:if test="umbraco.library:IsProtected(@id, @path) = 0 or (umbraco.library:IsProtected(@id, @path) = 1 and umbraco.library:IsLoggedOn() = 1)">
          
          <xsl:variable name="childMenuItems" select="./* [@isDoc and ( ( $Navigation.isSitemap != '1' and string(./umbracoNaviHide) = '0' ) or ( $Navigation.isSitemap = '1' and string(./umbracoSitemapHide) = '0' ) )]"/>
          <xsl:variable name="active" select="$currentPage [@isDoc]/@id=@id"/>
          <xsl:variable name="inpath" select="$currentPage/ancestor-or-self::* [@isDoc]/@id=@id"/>
          <xsl:variable name="firstitem" select="position() = 1"/>
          <xsl:variable name="lastitem" select="position() = $count"/>
          <xsl:variable name="hasChildren" select="count($childMenuItems) &gt; 0"/>
          <xsl:variable name="className">
            <xsl:if test="$active = '1' or $inpath = '1' or $firstitem = '1' or $lastitem = '1' or $hasChildren = '1'">
              <xsl:if test="$active = '1'">active</xsl:if>
              <xsl:if test="$inpath = '1' and $active = '1'"><xsl:text> </xsl:text></xsl:if>
              <xsl:if test="$inpath = '1'">inpath</xsl:if>
              <xsl:if test="$inpath = '1' and ($firstitem = '1' or $lastitem = '1')"><xsl:text> </xsl:text></xsl:if>
              <xsl:if test="$firstitem = '1'">firstitem</xsl:if>
              <xsl:if test="$firstitem = '1' and $lastitem = '1'"><xsl:text> </xsl:text></xsl:if>
              <xsl:if test="$lastitem = '1'">lastitem</xsl:if>
              <xsl:if test="($inpath = '1' or $firstitem = '1' or $lastitem = '1') and $hasChildren = '1'"><xsl:text> </xsl:text></xsl:if>
              <xsl:if test="$hasChildren = '1'"><xsl:text>hasChildren</xsl:text></xsl:if>
            </xsl:if>
          </xsl:variable>
          
          <li>
            <xsl:if test="$className != ''"><xsl:attribute name="class"><xsl:value-of select="$className" /></xsl:attribute></xsl:if>
            
            <a title="{@nodeName}">
              <xsl:if test="$className != ''"><xsl:attribute name="class"><xsl:value-of select="$className" /></xsl:attribute></xsl:if>
              <xsl:attribute name="href">
                <xsl:choose>
                  <xsl:when test="local-name() != 'ExternalLink'">
                    <xsl:value-of select="umbraco.library:NiceUrl(@id)" />
                  </xsl:when>
                  <xsl:otherwise>
                    <xsl:value-of select="./externalURL" />
                  </xsl:otherwise>
                </xsl:choose>
              </xsl:attribute>
              
              <xsl:value-of select="@nodeName" />
            </a>
            <xsl:if test=" number($currentLevel) &lt; number($Navigation.toLevel) and ( ( $inpath = '1' and string($Navigation.showOnlyCurrentPath) != '0' ) or string($Navigation.showOnlyCurrentPath) = '0' )">
              <xsl:call-template name="MenuItems">
                <xsl:with-param name="menuItems" select="$childMenuItems" />
                <xsl:with-param name="currentLevel" select="$currentLevel+1" />
                <xsl:with-param name="levelCounter" select="$levelCounter+1" />
              </xsl:call-template>
            </xsl:if>
          </li>
        </xsl:if>
      </xsl:for-each>
      
    </ul>
  </xsl:if>
  <!-- HTML END -->
</xsl:template>
</xsl:stylesheet>

Here's a look at my content tree, there are additional subcategories and products populated for the subcategories that are just not showing up.

Any suggestions, other than "learn more about XSLT"? :)