I am unclear if the XSL processing tools used by the Netbeans Enterprise pack
are provided with Netbeans, or with my JRE.  I may be filing this bug report in
the wrong place.

Using Netbeans to perform an XSL Transformation produces an incorrect result. 
It appears that this is a result of incorrectly evaluating statements like this:

select="root/data[count(. | $subset1) != count($subset1)]"

Applying this stylesheet:
----------------
<?xml version="1.0" encoding="UTF-8" ?>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
    <xsl:output method="html"/>

    <xsl:template match="/">
        <xsl:variable name="allNodes" select="root/data" />        
        <xsl:variable name="subset1" select="root/data[position() >3]" />        
        <xsl:variable name="subset2" select="root/data[count(. | $subset1) !=
count($subset1)]" />
        
        <xsl:element name="TransformationResults">
            <xsl:element name="SourceNodes">
                <xsl:attribute name="description">All nodes</xsl:attribute>
                <xsl:for-each select="$allNodes">
                    <xsl:copy-of select="." />
                </xsl:for-each>
            </xsl:element>
            
            <xsl:element name="Subset1">
                <xsl:attribute name="description">A subset of all
nodes</xsl:attribute>
                <xsl:for-each select="$subset1">
                    <xsl:copy-of select="." />
                </xsl:for-each>
            </xsl:element>
            
            <xsl:element name="Subset2">
                <xsl:attribute name="description">A subset of nodes calculated
(via Michael Kay's method) as 'All nodes' minus 'Subset 1'</xsl:attribute>
                <xsl:for-each select="$subset2">
                    <xsl:copy-of select="." />
                </xsl:for-each>
            </xsl:element>
        </xsl:element>
        
    </xsl:template>

</xsl:stylesheet>

----------------

To this document:
----------------
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="BugReportStyleSheet.xsl.xsl"?>

<root>
   <data>A</data>
   <data>B</data>
   <data>C</data>
   <data>D</data>
   <data>E</data>
   <data>F</data>
</root>

----------------

Produces this result when processed by whatever Netbeans uses:
----------------
<TransformationResults>
<SourceNodes description="All nodes">
<data>A</data>
<data>B</data>
<data>C</data>
<data>D</data>
<data>E</data>
<data>F</data>
</SourceNodes>
<Subset1 description="A subset of all nodes">
<data>D</data>
<data>E</data>
<data>F</data>
</Subset1>
<Subset2 description="A subset of nodes calculated (via Michael Kay's method) as
'All nodes' minus 'Subset 1'"/>
</TransformationResults>
----------------

And produces this result when processed by Xalan-J 2.7.0, by Saxon 6.5.5, and by
whatever Firefox 2.0.0.3 uses:
----------------
<transformationresults>
<sourcenodes description="All nodes">
<data>A</data>
<data>B</data>
<data>C</data>
<data>D</data>
<data>E</data>
<data>F</data>
</sourcenodes>

<subset1 description="A subset of all nodes">
<data>D</data>
<data>E</data>
<data>F</data>
</subset1>

<subset2 description="A subset of nodes calculated (via Michael Kay's method) as
'All nodes' minus 'Subset 1'">
<data>A</data>
<data>B</data>
<data>C</data>
</subset2>
</transformationresults>
----------------

Note that the contents of the 'Subset2' node differ between outputs.