.net webservice result always is NOTHING

Dhaest your help is appreciated if you can.

my webservice takes as parameter an OMElement and returns an OMElment, following is the webservice java implementation:

public OMElement getBodyParts2(OMElement element)
   {
      OMElement dataElement = element.getFirstElement();
      String xmlData = dataElement.getText();
      try
      {
         return dataElement;
      }
      catch(Exception e)
      {
         return null;
      }
  }

and here is the services.xml

<service name="BodyPartService" scope="application">
 <description> Body Part Web Service </description>
 <operation name="getBodyParts">
  <messageReceiver class="org.apache.axis2.receivers.RawXMLINOutMessageReceiver"/>
 </operation>
 <operation name="getBodyParts2">
 <messageReceiver class="org.apache.axis2.receivers.RawXMLINOutMessageReceiver"/>
 </operation>
 <parameter name="ServiceClass">com.compressus.wlclient.service.BodyPartService</parameter>
</service>


VB.net code that calls the webservice:
 Dim xx As New web.BodyPartService("localhost", 8080)
        Dim ds As New DataSet
        ds.EnforceConstraints = False
        ds.ReadXml("c:\data.xml")
        dim o = xx.getBodyParts2(ds.GetXml)
-------------------------------
my problem:
i was able to send the xml data taken from the file data.xml, but the return result is always nothing. any idea how can i fix that..
best.