application/xhtml+xml

Does validator even send application/xhtml+xml in Accept header?! It 
always complains that my page with such code:

$xhtml = false;
if(preg_match('/application\/xhtml\+xml(?![+a-z])(;q=(0\.\d{1,3}|[01]))?/i', 
$_SERVER['HTTP_ACCEPT'], $matches))
{
	$xhtmlQ = isset($matches[2])?$matches[2]:1;
	if($xhtmlQ!=0) $xhtml = true;
}
header('Content-Type: '.($xhtml?'application/xhtml+xml':'text/html').'; 
charset=utf-8');

has differences between Content-Type and DTD.

-- 
Nikodem
JID: nikn@jabber.org