Selecting node at a certain position from a nodeset

Hi,
  I want to select node at position $pos (e.g. $pos = number('1')) from a
  nodeset; here below are the XML-XSL sheets with which I have to work.
  Inside template "/doc" there are three "apply-templates" instructions:
  * the 1st selects all nodes satisfying the xpath conditions (this is
    showed only for debugging purpose)
  * the 2nd should select node at position $pos; instead it doesn't work!!
    Why??!?!?!!?
  * the 3rd select node at position $pos and works!!!
  So why doesn't the 2nd one work?
  Anyone has a better solution?
Thanks in advance!

XML:
<?xml version="1.0"?>

<doc>
        <sections>
                <section id="1" group="1">
                        <item id="1">item1-section1</item>
                        <item id="2">item2-section1</item>
                </section>
                <section id="2" group="2">
                        <item id="1">item1-section2</item>
                        <item id="2">item2-section2</item>
                </section>
                <section id="3" group="3">
                        <item id="1">item1-section3</item>
                        <item id="2">item2-section3</item>
                </section>
                <section id="4" group="1">
                        <item id="1">item1-section4</item>
                        <item id="2">item2-section4</item>
                </section>
                <section id="5" group="1">
                        <item id="1">item1-section5</item>
                        <item id="2">item2-section5</item>
                </section>
        </sections>
</doc>
 
XSL:
<?xml version="1.0"?>

<xsl:stylesheet version="1.0"
        xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
        xmlns:exsl="http://exslt.org/common"
>

<xsl:variable name="sections" select="/doc/sections"/>
<xsl:variable name="pos" select="1"/>

<xsl:template match="/doc">
        <xsl:apply-templates
select="$sections/section[@group=1]/item[@id=1]"/>
        <xsl:text>&#x0A;</xsl:text>
        <xsl:apply-templates
select="$sections/section[@group=1]/item[@id=1][$pos]"/>
        <xsl:text>&#x0A;</xsl:text>
        <xsl:apply-templates
select="exsl:node-set($sections/section[@group=1]/item[@id=1])[$pos]"/>
</xsl:template>

<xsl:template match="item">
        <xsl:apply-templates/>
        <xsl:text>&#x20;</xsl:text>
</xsl:template>

</xsl:stylesheet>

-------------------------------
Marco Guazzone
Software Engineer
Kerbero S.r.L. - Gruppo TC
Viale Forlanini, 36
Garbagnate M.se (MI)
20024 - Italy
mail: marco.guazzone@xxxxxxxxxxx
www: http://www.kerbero.com
Tel. +39 02 99514.247
Fax. +39 02 99514.399
--------------------------------


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