can you please post the html source you get in your browser when you get the error page?
this is what i get
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<style type="text/css">
body, th { font-family:tahoma, verdana, arial, helvetica, sans; font-weight:normal; font-size:9pt; }
body { background-color:#DDF; padding:10px; }
body, p, form { margin:0 }
a { text-decoration:none; background-color:Transparent; color:#05F; }
a:visited { color:#55F; }
a:hover { background-color:#EEF; }
img { border-style:none }
#files td { font-size:10pt; background:#FFF; border:1px solid #BBF }
#files td img { vertical-align:top }
#files th, th a, th a:visited { color:#555; font-size:13pt; font-weight:bold; padding-bottom:0; }
#foldercomment { font-size:10pt; color:#888; background:#EEE; padding:3px; border:1px solid #DDD; border-bottom:3px solid #DDD; margin-top:2px; }
#folder, .big { font-size:14pt; font-weight:bold; }
#folderlabel, #folderstats, #footer { font-size: 8pt; }
#body {
border-bottom: 4px solid #BBF;
border-top: 4px solid #BBF;
border-left: 1px dotted #BBF;
border-right: 1px dotted #BBF;
background:#F3F3FF;
padding:15px;
margin:15px;
}
.comment { font-size:7pt; color:#888; background:#EEE; padding:3px; border:1px solid #DDD; margin-top:2px; }
.button { height:24px; padding:4px 10px; margin:5px; border:2px solid black; background:white; font-size:8pt; font-weight:bold; }
a.button { padding:8px 10px; }
a.button img { vertical-align:text-bottom; }
.flag { font-weight:bold; font-size:8pt; background:white; color:red; text-align:center; border:1px solid red; }
.item-folder { font-size:smaller; margin-top:4px; }
</style>
</head>
<body>
<h1>Unauthorized</h1>
This is a protected resource.
<br>Your username/password doesn't match.
<hr>
<div style="font-family:tahoma, verdana, arial, helvetica, sans; font-size:8pt;">
<a href="http://www.rejetto.com/hfs/">HttpFileServer 2.3 beta</a>
<br>05/09/2008 12.07.02
</div>
</body>
</html>