/*************   UEXCEL NAV   *************/

/* Adapted from http://www.alistapart.com/articles/sprites/ */
#nav_smedia {
	width: 130px;
	height: 100px;
	background: url(/images/navigation/s_media.jpg) no-repeat;
	margin: 5px auto; 
	padding: 0;
	position: relative;
	float:right;
}

#nav_smedia ul {
	margin: 0;
	padding: 0;
}

#nav_smedia li {
	margin: 0; 
	padding: 0; 
	list-style: none; 
	top: 0;
	text-indent: -9999px;
}

#nav_smedia li, #nav_smedia a {height:50px;display:block; text-decoration: none; overflow: hidden;}

#nav_smedia #btn_twitter {width: 130px; left:0px; }
#nav_smedia #btn_facebook {width: 130px; background-position: 0px 50px; }
<!-- #nav_smedia #btn_optin {width: 130px; background-position: 0px 50px; } -->

#nav_smedia #btn_twitter a:hover {background: transparent url(/images/navigation/s_media.jpg); background-position: 0px 0px;}
#nav_smedia #btn_facebook a:hover {background: transparent url(/images/navigation/s_media.jpg); background-position: 0px -50px;}
<!-- #nav_smedia #btn_optin a:hover {background: transparent url(/images/navigation/s_media.jpg); background-position: -130px -50px;} -->