WebMethod returning XMLdataDocument

[patrick]

Hi all,
I am trying to consume a webservice that receives and returns XmlDataDocument ,
My problem is that the proxy created by VS.Net (by adding web reference) is changed so that the function receives & returns XmlNode instead of XmlDataDocument

So when I call the webService i get an Error: "Specified cast is not valid"
I found document from Microsoft that explains the problem at:
http://support.microsoft.com/default.aspx?scid=kb;en-us;330600

How do I call my web service function?
Thank you!
patrick

this is my web service :
///////////////////////////////////////////////////////////////////////////////////
[WebMethod]
public XmlDataDocument obtainXmlFromServer(XmlDataDocument whatTofind)
{
}
///////////////////////////////////////////////////////////////////////////////////
that's how the same function looks like in the proxi class :
///////////////////////////////////////////////////////////////////////////////////
[WebMethod]
public XmlNode obtainXmlFromServer(XmlNode whatTofind)
{
}
///////////////////////////////////////////////////////////////////////////////////