First item in Navigation — Hover CSS help?

What I want to do is make the first hovered link have a left radius border. I’m not sure of how to do this for the FIRST LI item only. Can anyone help?

here is some CSS for my menu/navigation on my site:

#nav {  clear: both;
	height: 45px;
	background: url(images/nav1.png);
	color: #FFFFFF;
	margin: 0 auto 0;
	padding: 0;
     border-top-right-radius: 10px;
     border-top-left-radius: 10px;
    -moz-border-radius-topright: 10px;
   -moz-border-radius-topleft:10px;
    -webkit-border-top-right-radius: 10px;
   -webkit-border-top-left-radius: 10px;
     border-bottom: 7px solid #f69c26;
	}
#nav .wrap {
	width: 960px;
	margin: 0 auto 0;
	} 

#nav ul {
	width: 100%;
	float: left;
	list-style: none;
	margin: 0;
	padding: 0;
	}

#nav li {
	float: left;
	list-style: none;
	margin: 0;
	padding: 0;
	}

#nav li a {
	background: url(images/nav1.png);
	color: #FFFFFF;
	display: block;
	font-family: Frutiger-Roman, Arial, Tahoma, Verdana;
	font-size: 11.53 pt;
        margin: 0;
	padding: 13px 15px 12px 15px;
	text-decoration: none;
	position: relative;
border-top-right-radius: 10px;
	border-top-left-radius: 10px;
    -moz-border-radius-topright: 10px;
	-moz-border-radius-topleft:10px;
    -webkit-border-top-right-radius: 10px;
	-webkit-border-top-left-radius: 10px;
	}

#nav li a:hover, #nav li a:active, #nav .current_page_item a {
	color: #453120; background: url(images/nav2.png);
	border-top-right-radius: 0px;
	border-top-left-radius: 0px;
    -moz-border-radius-topright: 0px;
	-moz-border-radius-topleft:0px;
    -webkit-border-top-right-radius: 0px;
	-webkit-border-top-left-radius: 0px;
	}

Any ideas?