this get ever more complicated :)

now i face another issue in last question we managed to take unique values from only one parent node

now with:

<?xml version="1.0" encoding="ISO-8859-1"?>
<roots>
     <root>
          <name>first</name>
          <item>
               <something>A</something>
               <something>A</something>
          </item>
          <item>
               <something>B</something>
               <something>A</something>
          </item>
          <item>
               <something>C</something>
               <something>P</something>
          </item>
          <item>
               <something>A</something>
               <something>L</something>
          </item>
          <item>
               <something>A</something>
               <something>A</something>
          </item>
          <item>
               <something>B</something>
               <something>A</something>
          </item>
          <item>
               <something>D</something>
               <something>A</something>
          </item>
     </root>
     <root>
          <name>second</name>
          <item>
               <something>E</something>
               <something>A</something>
          </item>
          <item>
               <something>B</something>
               <something>A</something>
          </item>
          <item>
               <something>F</something>
               <something>A</something>
          </item>
          <item>
               <something>A</something>
               <something>A</something>
          </item>
          <item>
               <something>A</something>
               <something>A</something>
          </item>
          <item>
               <something>B</something>
               <something>H</something>
          </item>
          <item>
               <something>D</something>
               <something>G</something>
          </item>
     </root>
</roots>

now i need to get the unique values depending only from one node before but just from the elements on the second position

  <?xml version="1.0" encoding="ISO-8859-1"?>
<xsl:stylesheet version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

  <xsl:output indent="yes" method="text"/>
  <xsl:key name="item-by-value" match="something"
 use="concat(normalize-space(.), ' ', generate-id(./ancestor::root))"/>
<xsl:key name="rootkey" match="root" use="name"/>
  <xsl:template match="/">
 <xsl:for-each select="key('rootkey','first')">
<xsl:for-each select="item/something[1]">
<xsl:sort />
  <xsl:if test="generate-id() = generate-id(key('item-by-value', 
                  concat(normalize-space(.), ' ', generate-id(./ancestor::root))))">
  <xsl:value-of select="."/>
 </xsl:if>
</xsl:for-each> 
<xsl:text>_________</xsl:text>
<xsl:for-each select="item/something[2]">
<xsl:sort />
  <xsl:if test="generate-id() = generate-id(key('item-by-value', 
                  concat(normalize-space(.), ' ', generate-id(./ancestor::root))))">
  <xsl:value-of select="."/>
 </xsl:if>
</xsl:for-each> 
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>

with this XSL i get ABCD__LP where the result i need is ABCD__ALP

any ideas?