A bit of firebugging revealed that the problem is caused by the vertical center hack. Simply put: it doesn't work that way.
Here's a much better vertical center hack, using table styles for IE8/Firefox/Chrome/... and relative positioning for IE6/7. I took the liberty to make it a bit more standards-compliant, but I didn't touch the table for the error message so the default style doesn't need changing.
html code:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head profile="http://gmpg.org/xfn/11">
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Messenger Skins » Search » KEYWORDS</title>
<link href="/skins/skins/default/style.css" rel="stylesheet" type="text/css" />
<meta http-equiv="refresh" content="3; url=/skins/browse/" />
<style type="text/css">
html, body {
width: 100%;
height: 100%;
margin: 0;
padding: 0;
}
#outer {
display: table;
width: 100%;
height: 100%;
overflow: hidden;
text-align: center;
}
#inner {
display: table-cell;
vertical-align: middle;
}
#message {
width: 40%;
margin: 0 auto;
text-align: center;
}
</style>
<!--[if lt IE 8]>
<style type="text/css">
#outer {
position: relative;
}
#inner {
position: absolute;
top: 50%;
left: 50%;
}
#message {
position: relative;
top: -50%;
left: -50%;
margin-top: -3.5em;
width: 100%;
}
</style>
<![endif]-->
</head>
<body>
<div id="outer">
<div id="inner">
<table id="message" cellpadding="3" cellspacing="0" class="border">
<tbody>
<tr class="sectionheader">
<th>Error</th>
</tr>
<tr>
<td>
<p>No results were found for "KEYWORDS". Please use the back button and try a different word.</p>
<p><a href="/skins/browse/">Click here if you are not redirected automatically.</a></p>
</td>
</tr>
</tbody>
</table>
</div>
</div>
</body>
</html>
/ 
