Hi koralex,
The problem is not the script itself but your theme or module that is rendering <header> twice!
Rendered code for
http://boashouse.com/modules/mastop_publish/?tac=aaa
<!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=ISO-8859-1" />
<meta http-equiv="content-language" content="en" />
<meta name="robots" content="index,follow" />
<meta name="keywords" content="BoA, BoA Kwon, BoA singer, boashouse, boa's house, boa japan, boa korea, korean singer, japanese singer, boa site, boa singer, BoA fansite, made in twenty, no.1 atlantis princess, outgrow, boa album, boa lyric, baoer, boa, boa kwon, boa singer, 보아, 권보아, missha, levis, boa discography, oricon, jpop, kpop, korean music, japanese music, doubleudot, smtown, fasio, merry chri, winter love, key of heart, nanairo no ashita, id peace b, listen to my heart, valenti, love and honesty, shine we are, jewel song, miodio, olympus, sketchers, amino calpis" />
<meta name="description" content="BoA's House - The No.1 Stop for BoA" />
<meta name="rating" content="general" />
<meta name="author" content="XOOPS" />
<meta name="copyright" content="" />
<meta name="generator" content="XOOPS" />
<title>BoA's House - aaa</title>
<link href="http://boashouse.com/favicon.ico" rel="SHORTCUT ICON" />
<link rel="stylesheet" type="text/css" media="all" href="http://boashouse.com/xoops.css" />
<link rel="stylesheet" type="text/css" media="all" href="http://boashouse.com/themes/7dana-Xred/styleNN.css" />
<!-- RMV: added module header -->
<meta http-equiv="Content-Script-Type" content="text/javascript" />
<meta http-equiv="Content-Style-Type" content="text/css" />
<script type="text/javascript" src="http://boashouse.com/include/xoops.js">
</script>
<script type="text/javascript">
<!--
//-->
</script>
<link rel="stylesheet" href="http://www.boashouse.com/themes/7dana-Xred/thumbnailviewer.css" type="text/css" />
<script src="http://www.boashouse.com/themes/7dana-Xred/thumbnailviewer.js" type="text/javascript">
/***********************************************
* Image Thumbnail Viewer Script- ¨Ï Dynamic Drive (www.dynamicdrive.com)
* This notice must stay intact for legal use.
* Visit http://www.dynamicdrive.com/ for full source code
***********************************************/
</script>
<link rel="stylesheet" type="text/css" href="http://boashouse.com/themes/7dana-Xred/balloontip.css" />
<script type="text/javascript" src="http://boashouse.com/themes/7dana-Xred/balloontip.js">
/***********************************************
* Rich HTML Balloon Tooltip- ¨Ï Dynamic Drive DHTML code library (www.dynamicdrive.com)
* This notice MUST stay intact for legal use
* Visit Dynamic Drive at http://www.dynamicdrive.com/ for full source code
***********************************************/
</script>
<script src="http://boashouse.com/imageload/js/prototype.js" type="text/javascript"></script>
<script src="http://boashouse.com/imageload/js/scriptaculous.js?load=effects" type="text/javascript"></script>
<script src="http://boashouse.com/imageload/js/lightbox.js" type="text/javascript"></script>
<link rel="stylesheet" href="http://boashouse.com/imageload/css/lightbox.css" type="text/css" media="screen" />
<script type="text/javascript" src="http://boashouse.com/themes/7dana-Xred/carouselscripts/prototype.js"></script>
<script type="text/javascript" src="http://boashouse.com/themes/7dana-Xred/carouselscripts/scriptaculous.js?load=effects"></script>
<script type="text/javascript" src="http://boashouse.com/themes/7dana-Xred/carouselscripts/frog.js"></script>
<style type="text/css">
#FrogJS{
width: 760px;
height: 600px;
margin: 0 auto;
}
#FrogJSCredit{
text-align: right;
font-size: 80%;
color: #999;
padding: 1px;
}
#FrogJSCaption{
text-align: left;
line-height: 140%;
}
</style>
</head>
[color=990000]
<head>
<meta http-equiv="content-type" content="text/html; charset=ISO-8859-1" />
<meta http-equiv="content-language" content="en" />
<meta name="robots" content="index,follow" />
<meta name="keywords" content="BoA, BoA Kwon, BoA singer, boashouse, boa's house, boa japan, boa korea, korean singer, japanese singer, boa site, boa singer, BoA fansite, made in twenty, no.1 atlantis princess, outgrow, boa album, boa lyric, baoer, boa, boa kwon, boa singer, 보아, 권보아, missha, levis, boa discography, oricon, jpop, kpop, korean music, japanese music, doubleudot, smtown, fasio, merry chri, winter love, key of heart, nanairo no ashita, id peace b, listen to my heart, valenti, love and honesty, shine we are, jewel song, miodio, olympus, sketchers, amino calpis" />
<meta name="description" content="BoA's House - The No.1 Stop for BoA" />
<meta name="rating" content="general" />
<meta name="author" content="XOOPS" />
<meta name="copyright" content="" />
<meta name="generator" content="XOOPS" />
<title>BoA's House - aaa</title>
<link href="http://boashouse.com/favicon.ico" rel="SHORTCUT ICON" />
<link rel="stylesheet" type="text/css" media="screen" href="http://boashouse.com/xoops.css" />
<link rel="stylesheet" type="text/css" media="screen" href="http://boashouse.com/themes/7dana-Xred/styleNN.css" />
<!-- RMV: added module header -->
<meta http-equiv="Content-Script-Type" content="text/javascript" />
<meta http-equiv="Content-Style-Type" content="text/css" />
<script type="text/javascript" src="http://boashouse.com/include/xoops.js">
</script>
<script type="text/javascript">
<!--
//-->
</script>
</head>[/color]