WebPlus X5: Submitting Sitemaps

When I look for the site map
http://www.ospreypools.co.uk/sitemap.xml

There is a meesage above which says:
This XML file does not appear to have any style information associated with it. The document tree is shown below.

I'm assuming it means the version
<?xml version="1.0" encoding="UTF-8"?>

Which I'm assuming again comes from uploading the website from webplusX5

Any ideas why the version is being left out?

Many thanks all

John