I have a question, in the original for 2.6 it has this:

Code:
echo "<?xml version='1.0' encoding='iso-8859-1'?>";
echo "<urlset xmlns='http://www.sitemaps.org/schemas/sitemap/0.9' xmlns:video='http://www.google.com/schemas/sitemap-video/1.0'>";
Would the reference to the fact that this is for videos be of any importance?