<assign fromexpr=.....> failed to pass xml fragment to <invoke inputvariables=....>

Hi

<invoke ... inputvariables="inputVariable"  ...> seems not to take the full xml value from <assign fromexpr="an xpath" outputvariable="inputVariable" >

I had 2 simple mashups: TestMashupWsdlClient and TestMashupWsdl.  TesMashupWsdlClient created an input variable from <assign fromexpr=.....> and pass it to mashup TestMashupWsdl. The TestMashupWsdl printed out the input value from TestMashupWsdl Client.

If I used <assign fromvariable="" .... > to add an xml tree to the input variables of the <invoke>, the TestMashupWsdl, the TestMashupWsdl was able to print the full input xml tree.

If used <assign fromexpr=....> , the TestMashupWsdl only printed out the top-level element name of the xml tree with xmlns="".

Is there an known issue with <assign fromexpr=....> and <invoke inputvariables= >?

TestMashupWsdlClient:

<mashup xmlns:xsi= "http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://www.jackbe.com/2008-03-01/EMMLSchema/ ../src/schemas/EMMLSpec.xsd"
      xmlns="http://www.jackbe.com/2008-03-01/EMMLSchema"
      xmlns:macro="http://www.jackbe.com/2008-03-01/EMMLMacro"
      xmlns:testing="testing"
      name = "TestMashupWsdlClient">
     <operation name="invoke">
     <variable name="testInput" type="document" >
       <test xmlns="testing">
          <testItem>1</testItem>
          <testItem>2</testItem>
       </test>
    </variable>
   
    <!--
    <assign fromvariable="testInput" outputvariable="inputToTestMashupWsdl" />
     -->
    
    <assign fromexpr="$testInput/testing:test" outputvariable="inputToTestMashupWsdl" />
    <display message="inputToMashupWsdl before invoke = " variable="inputToTestMashupWsdl" />
     <invoke service="TestMashupWsdl" operation="invoke" inputvariables="inputToTestMashupWsdl" outputvariable="searchRequest" /> 
 
    <output name="soapResponse" type="document">
      <result xmlns="testnamespace" />
    </output>
   
 </operation>  
 </mashup>

TestMashupWsdl:

<mashup xmlns:xsi= "http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://www.jackbe.com/2008-03-01/EMMLSchema/ ../src/schemas/EMMLSpec.xsd"
      xmlns="http://www.jackbe.com/2008-03-01/EMMLSchema"
      xmlns:macro="http://www.jackbe.com/2008-03-01/EMMLMacro"
      name = "TestMashupWsdl">
 <operation name="invoke">
    <input name="soapRequest" type="document" />
     <display message="soapRequest = " variable="soapRequest" />
    <output name="soapResponse" type="document">
      <result xmlns="testnamespace" />
    </output>
 </operation>  
 </mashup>

Log when using <assign fromexpr=....>

soapRequest =     <?xml version="1.0" encoding="UTF-8"?>
<test>null</test>

Any ideas?

Thanks in advance