strangely, this works...

[email protected] ("Steph Fox") Mon, 10 Jul 2006 19:46:52 +0200

Newsgroups	php.gtk.webmaster
Message-ID	<07ca01c6a448$d751f130$6602a8c0@foxbox>

 ob_start();
echo "<?xml version='1.0' encoding='UTF-8'?>\n";
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
 <meta content="text/html; charset=UTF-8" http-equiv="Content-Type" />
...

OK so it makes it invalid again, but a) it doesn't cause any problems with 
display and b) the page I validated had HTML errors in it that I hadn't 
noticed until the validator told me!

It'd make sense to me to switch, given that 4.01 fights back and 4.0 is 
antiquated.

Thoughts?