rss feed error "XML or text declaration not at start of entity Location"

[eluser]SitesByJoe[/eluser]
I'm running into the same error. Here's my controller for testing:

Code:

<?php
class Sitemap extends Controller {
    
        function Sitemap()
        {
                parent::Controller();
        }
        
        function index()
        {
                echo header("Content-Type: text/xml");
                echo '<?xml version="1.0" encoding="UTF-8" ?>';
        }
}
?>

With no other spaces being added, its certainly a mystery where its coming from...

Anyone figure this out?