title: Changing XML node attribute value gives "Namespace error"
body: <p>I use TXMLDocument to create XML documents. Sometimes I need to change attribute values. I get a "Namespace error" if I use the "ADOM XML v4" DOM vendor (Delphi XE2). </p>
  
  <p>Example code:</p>
  
  <pre><code>procedure TForm1.Button1Click(Sender: TObject);
  var
    XML: TXMLDocument;
    XMLNode, XMLSubNode: IXMLNode;
  begin
    XML := TXMLDocument.Create(nil);
    //XML.DOMVendor := GetDOMVendor('MSXML'); // Works using MSXML
    XML.DOMVendor := GetDOMVendor('ADOM XML v4');
    XML.Active := True;
    XMLNode := XML.AddChild('test');
    XMLNode.Attributes['state'] := 1;
    XMLNode.Attributes['state'] := 0; // Raises "Namespace error"
  end;
  </code></pre>
  
  <p>If I use MSXML, then everything works fine. I want to use ADOM XML because I'm generating large XML files and it seems to be a lot faster than MSXML. </p>
  
  <p>How do I change the attribute value?</p>