Another Works IE; FF 100% height Fails

Basically it works fine in IE but in FF the scroll bar doesnt show up and it just forces everything down. Theres a scroll bar in a div tag in the middle of the table.

http://www.templarian.com/misc/kirupa/example.html

<!-- Copyright ©2006 Templarian, CMS -->
<html>
<head>
<title>Templarian Content Management System</title>
<style type="text/css">
body,html{margin:0px;width:100%;height:100%;font-family:Trebuchet MS, Tahoma, Arial, Helvetica, sans-serif;overflow:hidden;}
#t_main{width:100%;height:100%;}
#t_top{height:28px;background:url(x/x_img/gui_top.png);color:#8994A1;font-size:16px;padding-left:45px;}
#t_bottom{height:28px;background:url(x/x_img/gui_bottom.png);color:#8994A1;font-size:16px;text-align:right;padding-right:10px;}
#t_middle{position:relative;width:100%;height:100%;overflow:auto;}
</style>
</head>
<body>
<table id="t_main" cellpadding="0" cellspacing="0">
<tr>
<td id="t_top">Menu</td>
</tr>
<tr>
<td>
<div id="t_middle">
1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1<br />1
</div>
</td>
</tr>
<tr>
<td id="t_bottom" class="clear">Copyright 2006 Templarian</td>
</tr>
</table>
</body>
</html>

Thanks.

(The real version is a built into a CMS so I can’t really post it if no ones able to answer then i will make up a test version.)