For me, specifically, it breaks it in gallery templates because for the gallery, and the gallery only, it goes after the line
Code:
<base href="http://athanatoi.quillsabroad.com/forums/index.php" />
<!-- WoWHead Mouseover-Tooltips -->
<script src="http://www.wowhead.com/widgets/power.js" type="text/javascript"></script>
And it needs to go before it. Searching for a way to get it inserted before the base url, but not finding it

(On forum pages it is inserted first.)
Double the edit. I fixed the problem by editing the shell_blank template
Code:
$stylevar[htmldoctype]
<html dir="$stylevar[textdirection]" lang="$stylevar[languagecode]">
<head>
<script src="http://www.wowhead.com/widgets/power.js" type="text/javascript"></script>
$headinclude
<title>$pagetitle</title>
</head>
<body>
$header
$navbar
$html
$footer
</body>
</html>
Of course, I think I have the wowhead script url twice on my page now, so have to find where the addon inserts it >>