ul#menu2 li a {
background:url(images/sprite_videos.png) no-repeat scroll top left;
display:block;
height:32px;
position:relative;
}

ul#menu2 li a span {
background:url(images/sprite_videos.png) no-repeat scroll bottom left;
display:block;
position:absolute;
top:0;
left:0;
height:100%;
width:100%;
z-index:100;
}