Sorry, Clicken, I'm neither familiar with XML or MS FP. In my book, "microsoft works" is an oxymoron of our generation.
Have you looked at
http://www.w3.org/TR/1999/REC-xml-na.../Overview.html
Does it need a "disclaimer" above like
<?xml version="1.0"?>
Sorry, just grasping at straws, but thought it might be worth a looksy/try.