Key function using key strings from msxsl:node-set gen

I have a baffling problem. I'm trying to call the key function using strings extracted from nodes coming from the  msxsl:node-set function. No matter what I try (i.e. normalize-space etc) I can't get the same string from msxsl:node-set as I do from the raw XML.

There's a good reason why I don't want to use the Muenchian method (which works fine). But I won't bore you with that. I've created a simple example which illustrates the point. 
Any help would be greatly appreciated. 

cheers

Malcolm


<?xml version="1.0" encoding="UTF-8"?>

<?xml-stylesheet type="text/xsl" href="Table from keys.xsl"?>
<People>
	<Person>
		<Name>Malcolm</Name>
		<Address>
			<No>10</No>
			<Street>Lime Close</Street>
		</Address>
	</Person>
	<Person>
		<Name>Peter</Name>
		<Address>
			<No>20</No>
			<Street>Milner Rd</Street>
		</Address>
	</Person>
	<Person>
		<Name>Mary</Name>
		<Address>
			<No>20</No>
			<Street>Milner Rd</Street>
		</Address>
	</Person>
	<Person>
		<Name>John</Name>
		<Address>
			<No>20</No>
			<Street>Milner Rd</Street>
		</Address>
	</Person>
</People>


<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:msxsl="urn:schemas-microsoft-com:xslt">
	<xsl:preserve-space elements="*"/>
	<!-- 
	
	key giving Person by the raw address string-->
	<xsl:key name="PersonByAddress" match="/People/Person" use="Address"/>
	<!-- 
	
	Address string key so unqiue addresses can a extracted by Muenchian method-->
	<xsl:key name="Address" match="/People/Person/Address" use="."/>
	<!-- 
	
	Alternative to Muenchian method - a ready-made list of the unique addresses-->
	<xsl:variable name="UniqueAddressStrings">
		<Address>
			<No> 10</No>
			<Street>Lime Close</Street>
		</Address>
		<Address>
			<No> 20</No>
			<Street>Milner Rd</Street>
		</Address>
	</xsl:variable>
	<!--

	-->
	<xsl:template match="/">
		<!-- 
		
		-->
		<p>Works: Table contents keyed by unique address strings, determined on-the-fly by Muenchian method</p>
		<!--
		
		 -->
		<table border="1" cellspacing="0">
			<tr>
				<td>Address</td>
				<td>No. of people</td>
			</tr>
			<xsl:for-each select="/People/Person/Address[generate-id(.)=generate-id(key('Address',.)[1])]">
				<xsl:sort select="."/>
				<tr>
					<td>
						<xsl:value-of select="."/>
					</td>
					<td>
						<xsl:value-of select="count(key('PersonByAddress',.))"/>
					</td>
				</tr>
			</xsl:for-each>
		</table>
		<!-- 
		
		-->
		<p>Doesn't work: Table contents keyed by unique address strings, extracted from a unique list of address included in the XSLT. Requires msxsl:node-set, but cannot get the same string nodes created by node-set function. Normalize-space does not seem to help.</p>
		<!--
		
		 -->
		<table border="1" cellspacing="0">
			<tr>
				<td>Address</td>
				<td>No. of people</td>
			</tr>
			<xsl:for-each select="msxsl:node-set($UniqueAddressStrings)/Address">
				<xsl:sort select="."/>
				<tr>
					<td>
						<xsl:value-of select="normalize-space(.)"/>
					</td>
					<td>
						<xsl:value-of select="count(key('PersonByAddress',normalize-space(.)))"/>
					</td>
				</tr>
			</xsl:for-each>
		</table>
	</xsl:template>
</xsl:stylesheet>




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