First try at using set:distinct not going well, need help

I am using XMLSPY and have it set to use the MSXML parser

If I'm understanding some of the previous entries here on the list, MSXML
can't handle the function call
      node-set set:distinct(node-set)
style  and you have to use the template call
      <xsl:call-template name="set:distinct">
         <xsl:with-param name="nodes" select="node-set" />
      </xsl:call-template>

when I try to run the template I get a failure with "Named
template'{http://exslt.org/set}distinct' does not exist in the stylesheet"
as the error message.

What am I missing here?

<xsl:stylesheet
     xmlns:util="http://www.jclark.com/xt/java/glog.webserver.util.Util"

xmlns:translator="http://www.jclark.com/xt/java/glog.webserver.i18n.Translator"

     xmlns:xt="http://www.jclark.com/xt"
     xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0"
     xmlns:set="http://exslt.org/set" extension-element-prefixes="set">
<xsl:import href="file://C:\TransOvalAsturias\xsl\workflow\set.xsl"/>
....
TESTING DISTINCT SETS <br/>
<xsl:call-template name="set:distinct">
   <xsl:with-param name="nodes"
   select="(//TenderOffer/Shipment/TransOrder/ShipUnitDetail/ShipUnit[ShipUnitGid/Gid/Xid=$orderNumber]/ShipUnitContent/Remark[RemarkQualifierGid/Gid/Xid
 = 'PRODUCT_NAME']/RemarkText)"/>
</xsl:call-template>
<xsl:value-of select="."/>

THANKS IN ADVANCE!!!
- Craig