Muenchian troubles - only getting first group - Help

I am having trouble with Muenchian grouping. I want to add up the charges, by type. I expect in this particular example to output two <Total_Charge_By_Type ... /> elements, but only one is outputted! 

Here is the example XML :

<Account>
  <Service Name="A Service" Service_Id="89150" >
	<Feature Name="Extents" Feature_Id="203943" Status="65">
		<Charge Trans_Type_Name="Extent" Bucket_Type="1">
			<Trans_Class>R</Trans_Class>
			<Charge_Amount>
				<Amount Currency_Cd="EUR">467.55</Amount>
			</Charge_Amount>
		</Charge>
	</Feature>
	<Feature Name="Service Accumulator" Feature_Id="567528" Status="65">
	  <Total_Charge>
		<Charge_Amount>
			<Amount Currency_Cd="EUR">0</Amount>
		</Charge_Amount>
	  </Total_Charge>
	</Feature>
	<Feature Name="Storage" Feature_Id="267663" Status="65">
		<Charge Trans_Type_Name="Pages" Bucket_Type="1">
			<Trans_Class>R</Trans_Class>
			<Charge_Amount>
				<Amount Currency_Cd="EUR">16.64</Amount>
			</Charge_Amount>
		</Charge>
		<Charge Trans_Type_Name="Pages" Bucket_Type="1">
			<Trans_Class>R</Trans_Class>
			<Charge_Amount>
				<Amount Currency_Cd="EUR">0.64</Amount>
			</Charge_Amount>
		</Charge>
	</Feature>
  </Service>
</Account>


In the template that processes the <Account>, the Account is current at that time it calls the template "muench_chargetypenames" to do the summing: 

....
<!-- Now, Add up and nest in the Charges within the Services within this Account		-->
	<xsl:if test="Service">
		<xsl:element name="Total_Charge">
			<xsl:attribute 	name="Amount"> 
				<xsl:value-of select=
"sum( Service//Charge[not(Trans_Class=&quot;I&quot;)]/Charge_Amount/Amount)" />
			</xsl:attribute>	
			<xsl:attribute name="Flag" >
				<xsl:value-of select="HasSvc" />
			</xsl:attribute>	
		</xsl:element>
<!-- Also, add up and nest in the Charges divided into separate Transaction type names 	--> 
		<xsl:call-template name="muench_chargetypenames"/>
	</xsl:if>	
	<xsl:if test="not(Service)">
<Total_Charge Amount="0" Flag="NoSvc" />			
	</xsl:if>
.....

The key is defined according to the attribute @Trans_Type_Name of the Charge element:

<xsl:key name="TransTypes" 
	match="Charge[Trans_Class='R']" 
	use="@Trans_Type_Name"/>


And here is muench_chargetypenames :

<xsl:template name="muench_chargetypenames" >	
	<xsl:message>
Hey, in muench_chargetypenames 
Current element name <xsl:value-of select="local-name(.)"/>
	</xsl:message>	
	<xsl:for-each select="Service/Feature/Charge[generate-id()=generate-id(key('TransTypes',@Trans_Type_Name)[1])]">
		<xsl:variable name="ThisType" select="@Trans_Type_Name"></xsl:variable>
		<xsl:message>           	
Hey, Total By Type, type is  <xsl:value-of select="@Trans_Type_Name"/> ,  Amount of this one is  <xsl:value-of select="Charge_Amount/Amount"/>   			
		</xsl:message>               	 
		<xsl:element name="Total_Charge_By_Type">
			<xsl:attribute name="Amount"> 
			  <xsl:value-of select=
"sum(../../../Service/Feature/Charge[Trans_Class='R' and @Trans_Type_Name=$ThisType]/Charge_Amount/Amount)" />
			</xsl:attribute>	
			<xsl:attribute name="Trans_Type_Name" >
				<xsl:value-of select="@Trans_Type_Name" />
			</xsl:attribute>	
		</xsl:element>
  	</xsl:for-each>
</xsl:template>	


The message output shows that the for-each is looping only once, for type "Pages", but there should be a second time for "Extent". Why not? 

( There could have been more Services, but in this example there are not.)
( I could have used ancestors::Account instead of ../../.. , but that part is working. )