[Plugin: Google XML Sitemaps] 404 error on line 3, col 6 : XML declaration

My sitemap is supposed to be at :

http://www.scissorpaperstone.com/sitemap.xml

but when I look at the URL, it says this:

This page contains the following errors:

error on line 3 at column 6: XML declaration allowed only at the start of the document
Below is a rendering of the page up to the first error.

Any ideas much appreciated, thanks

http://wordpress.org/extend/plugins/google-sitemap-generator/