Character encoding not declared in html document
===

I have a file that I am getting a very weird error on.  The error is:

    The character encoding of the HTML document was not declared. 
    The document will render with garbled text in some browser configurations if 
    the document contains characters from outside the US-ASCII range. 
    The character encoding of the page must to be declared in the document or 
    in the transfer protocol.

the file this comes from is (indexmws.php):

    session_start();
    if(!isset($_SESSION['validUser']) || $_SESSION['validUser'] !== true){
    header('Location: loginmws.php');
    }

    include_once('db.php');
    include_once('amazonmws.php');
    include_once('decidemws.php');
    include_once('author.php');
    include_once('amazonPricingMWS.php');

    ?>

    <!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 http-equiv="Content-Type" content="text/html; charset=utf-8"/>
		<title>Decision Maker</title>

This is an exact duplicate of a file that does not throw the error (index.php)with the exception of adding amazonPricingMWS.php and redirecting to pages with mws.php in the title:

    session_start();
    if(!isset($_SESSION['validUser']) || $_SESSION['validUser'] !== true){
    header('Location: login.php');
    }

    include_once('db.php');
    include_once('amazon.php');
    include_once('decide.php');
    include_once('author.php');

    ?>

    <!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 http-equiv="Content-Type" content="text/html; charset=utf-8"/>
		<title>Decision Maker</title>

can anyone explain to me why I am getting this error in indexmws.php?