Problem creating xml file

Why is the <string> tag generated?
How can I get rid of it?
I don't want anything to wrap my xml-code.
I have tried many different variants ...

Here is some typical code:
doc.LoadXml("<?xml version=\"1.0\" encoding=\"utf-8\"?><Projects />");
doc.Save(Server.MapPath("ourProjects.xml"));

The resulting xml:
<?xml version="1.0" encoding="utf-8" ?>
<string xmlns="http://www.somepath/WebServices">
<?xml version="1.0" encoding="utf-8"?><Projects />
</string>

 

I'm not sure if this can be done. I believe the string tag is a .net standard for web services.