I'm building a "highlighted product" kind of widget using the following XSLT:

<?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.ExsltMath="urn:Exslt.ExsltMath"
    exclude-result-prefixes="msxml umbraco.library Exslt.ExsltMath">

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

<xsl:param name="currentPage"/>
<xsl:variable name="bannerFolder" select="1060"/>

<!-- ============================================================= -->

<xsl:template match="/">
    <xsl:variable name="numNodes" select="count(umbraco.library:GetXmlNodeById($bannerFolder)/node)"/>
    <xsl:variable name="random" select="floor(Exslt.ExsltMath:random() * $numNodes) + 1"/>
<table>
<tr>
<xsl:if test="umbraco.library:GetXmlNodeById($bannerFolder)/node[position() = $random]/node[position() = $random]/data[@alias='produktbillede'] != ''"> 
<td style="vertical-align: top;"><a href="{umbraco.library:GetMedia(umbraco.library:GetXmlNodeById($bannerFolder)/node[position() = $random]/node[position() = $random]/data[@alias='produktbillede'],false)/data[@alias='umbracoFile']}"><img src="/umbraco/ImageGen.ashx?image={umbraco.library:GetMedia(umbraco.library:GetXmlNodeById($bannerFolder)/node[position() = $random]/node[position() = $random]/data[@alias='produktbillede'],false)/data[@alias='umbracoFile']}&amp;height=100" /></a></td>
</xsl:if>
<td  style="vertical-align: top;"><strong><xsl:value-of select="umbraco.library:GetXmlNodeById($bannerFolder)/node[position() = $random]/node[position() = $random]/data [@alias='produktnavn']"/></strong><br />
             <xsl:value-of select="umbraco.library:GetXmlNodeById($bannerFolder)/node[position() = $random]/node[position() = $random]/data [@alias='kortbeskrivelse']"/></td>
</tr>
</table>
</xsl:template>

I'm having some difficulties getting it to work correctly with the following menu structure:

Root
|-- Category A
|---- Item 1
|---- Item 2
|-- Category B
|---- Item 1
|---- Item 2

The script seems to always select the same items in each category