modificar nodo de un xml

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim writer As New XmlTextWriter("Facturas.xml", System.Text.Encoding.UTF8)
        writer.WriteStartDocument(True)
        writer.Formatting = Formatting.Indented
        writer.Indentation = 2
        writer.WriteStartElement("factura")
        writer.WriteAttributeString("id", "comprobante")
        writer.WriteAttributeString("version", "1.0.0")

        writer.WriteComment("...........")
        writer.WriteComment("...........")

        writer.WriteEndElement()
        writer.WriteEndDocument()
        writer.Flush()
        writer.Close()


    End Sub

Curioso, si invierto el orden sale bien

writer.WriteAttributeString("version", "1.0.0")
writer.WriteAttributeString("id", "comprobante")

[W]