in the 3col.css file, change:
#nav {
padding: 0px;
clear: both;
float: right;
margin-top: 20px;
margin-right: 0px;
margin-bottom: 0px;
margin-left: 0px;
width: 820px;
}
to:
#nav {
padding: 0px;
clear: both;
float: right;
margin-top: 20px;
margin-right: 0px;
margin-bottom: 0px;
margin-left: 0px;
width: 820px;
position: relative;
z-index: 1;
}