Can't generate xml site

Hi!

I can’t generate xml files because this error:

“This page contains the following errors:

error on line 6 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.”

I checked function.php and nowhere found whitespace.

Any idea?
My site: http://www.kattanjra.com

http://wordpress.org/extend/plugins/wordpress-seo/