>I don't see a need for you to change the way the header is generated. The XML fragment you are receiving is correct as far as the W3C recommendation is concerned.
>
>All you need to do is to adapt your code to use XML Namespace prefixes in the XPath expressions. The XPath 1.0 specification doesn't support default XML Namespaces (Namespaces without a prefix). So, as your XML fragment uses a default namespace, you need a way to map it with a prefix and this is what the SetProperty/SelectionNamespaces is doing.
>
>Does this make sense?

Well, this is the SOAP header on the client side for the IHeaderHandler_readHeader event:

PROTECTED FUNCTION IHeaderHandler_readHeader(toReader As MSSOAPLib30.ISoapReader,;
 toHeaderNode As MSXML2.IXMLDOMNode,toObject As Object) AS Boolean
IF toHeaderNode.baseName<>'EnteteHere' OR toHeaderNode.namespaceURI<>'http://tempuri.org/MyHeader'
   RETURN .F.
ENDIF

* Adjust namespace so MSXML4 can be used
* Otherwise, SelectSingleNode() won't work
toHeaderNode.SetProperty('SelectionNamespaces',"xmlns:x='http://tempuri.org/MyHeader'")

This.FirstNode=toHeaderNode.SelectSingleNode('/x:EnteteHere/x:FirstNode').Text

RETURN .T.
ENDFUNC

The problem is that MSXML2.IXMLDOMNode doesn't include the SetProperty() method.