xforms:setvalue from XPL pipeline on xxforms:instance value

Hi,

I would like to monitor the progress of a XPL pipeline in which I have a oxf:xforms-submission processor.
A setvalue is fired when the submission is done (ev:event="xforms-submit-done") but the target instance is not found.

Is it the right way to do that ?
you can see my example in the file attached.

Thanks


2010-10-28 00:18:11,734 INFO  ProcessorService  - /currency-converter/services/ConversionRate - Received request
2010-10-28 00:18:13,312 WARN  XFormsServer  -                   xxforms:instance() - instance not found {instance id: "ConversionRate-step"}




<p:processor name="oxf:xslt">
  <p:input name="data" href="#instance"/>
    <p:input name="config">
      <xsl:stylesheet version="2.0">
        <xsl:template match="/">
          <xforms:submission method="post"
        action="http://www.webservicex.net/CurrencyConvertor.asmx"
        mediatype="text/xml; action=http://www.webserviceX.NET/ConversionRate">
        <xforms:setvalue ev:event="xforms-submit-done"  
            ref="xxforms:instance('ConversionRate-step')/result/step">1</xforms:setvalue>
        </xforms:submission>
          </xsl:template>
       </xsl:stylesheet>
   </p:input>
   <p:output name="data" id="submission"/>
 </p:processor>currency-converter.zip