For some reason, I am not entirely sure why, but the following is not working. The background position simply stays the same on hover. I cannot figure out why. I could do it another way, but I would like to try and get to the bottom of why it does not work.

#nav a:link, #nav a:visited {
    background:url(../img/nav-sprite.png) no-repeat;
    display:block;
    float:left;
    height:200px;
    padding:10px;
    text-indent:-9999px;
    border:solid 1px red;
}

    #nav a#home {
        background-position:-10px 0px;
        width:30px;
    }
    #nav a#about-us {
        background-position:-85px 0px;
        width:45px;
    }

#nav a:hover    {
    background-position:1px -15px;
}

Does anybody know what could be causing this?

Thanks in advance!

Ryan