Float right is making background-color disappear in IE while hovering.

Question

Everything works OK in this language menu: http://alexchen.co.nr/beta (top right of the page). But I want the li elements to float to the right. But when I add float:right to #lang li a the background-color stop working while hovering when I hover them in IE7.

#lang {
    float: right;
    padding: 50px 25px 0 0px;
    margin: 0 0 0 0px;
    width: 295px;
}
#lang li {
    font-size: 10px;
    width: 325px; /*ie hack */
}
#lang li a {
    color: #FFF;
    padding: 5px 25px 5px 249px;
    line-height: 220%;
}
#lang li a:hover {
    color: #444;
    background-color: #FFF;
}
#lang li.current a {
    color: #444;
    background-color: #FFF;
    cursor: default;
}