Problems with CSS menu in Internet Explor

Hey there
I've put together a drop down CSS menu. It works fine in Firefox but when I view it in Internet Explorer it doesn't work at all- any suggestions. The code for the page is displayed below:

Blastbeat

body,td,th {
font-family: Verdana, Arial, Helvetica, sans-serif;
font-size: 12px;
color: #FFFFFF;
}
ul{
padding: 0;
margin: 0;
list-style: none;
}

li {
float: left;
position: relative;
width: 10em;
height: 2em;
color: #FFFFFF;
background: #BF0000;
padding: 5px;
border: 1px solid #ccc;
border-bottom: 1px solid #ccc;
}

li ul {
display: none;
position: absolute;
top: 1em;
left: 0;
}

li > ul {
top: auto;
left: auto;
}
li:hover ul, li.over ul{ display: block; }
clear: left
a:link {
color: #FFFFFF;
text-decoration: none;
}
a:visited {
color: #FFFFFF;
text-decoration: none;
}
a:hover {
color: #FFFFCC;
text-decoration: none;
}
a:active {
text-decoration: none;
}
a:link {
color: #FFFFFF;
text-decoration: none;
}
body {
background-color: #000000;
}