hey all!

I'm constructing a horizontal dropdown menu and like usual, works perfect in FireFox, and not at all in IE. I'm having troubles getting the menu items to display in IE, can anyone offer a suggestion? thanks!

HTML:
Code:
<div id="top_nav_container">
									<div><img src="images/topnav_top.gif" height="5"></div>
									<ul id="topnav">
					<li class="top_top"><a href="#" class="drop"><img src="images/nav/btn_ms.jpg" border="0" align="left"></a>
						<ul>
							<li><a href="#" class="enclose">Getting Started</a></li>
							<li><a href="#" class="enclose">Markets We Serve</a></li>
							<li><a href="#" class="enclose">Products and Services</a></li>
							<li><a href="#" class="enclose">Merchant Resources</a></li>
							<li><a href="#" class="enclose">Fraud Protection</a></li>
							<li><a href="#" class="enclose">Sent Me information</a></li>
						</ul>
					</li>
					<li class="top_top"><a href="#" class="drop"><img src="images/nav/btn_baa.jpg" border="0" align="left"></a>
						<ul>
							<li><a href="#" class="enclose">Agent Benefits</a></li>
							<li><a href="#" class="enclose">Tools and Recources</a></li>
							<li><a href="#" class="enclose">Products and Services</a></li>
							<li><a href="#" class="enclose">agent application</a></li>
							<li><a href="#" class="enclose">FAQ</a></li>
							<li><a href="#" class="enclose">Sent Me information</a></li>
						</ul>
					</li>
					<li class="top_top"><a href="#" class="drop"><img src="images/nav/btn_pas.jpg" border="0" align="left"></a>
						<ul>
							<li><a href="#" class="enclose">Markets We Serve</a></li>
							<li><a href="#" class="enclose">Credit</a></li>
							<li><a href="#" class="enclose">Debit</a></li>
							<li><a href="#" class="enclose">E-commerce</a></li>
							<li><a href="#" class="enclose">Wireless</a></li>
							<li><a href="#" class="enclose">Checks</a></li>
							<li><a href="#" class="enclose">Gift Cards</a></li>
							<li><a href="#" class="enclose">EBT</a></li>
							<li><a href="#" class="enclose">Fraud Protection</a></li>
							<li><a href="#" class="enclose">Call Centers</a></li>
							<li><a href="#" class="enclose">Business to business</a></li>
							<li><a href="#" class="enclose">Send me information</a></li>
						</ul>
					</li>
					<li class="top_top"><a href="#" class="drop"><img src="images/nav/btn_au.jpg" border="0" align="left"></a></li>
					<li class="top_top"><a href="#" class="drop"><img src="images/nav/btn_po.jpg" border="0" align="left"></a>
						<ul>
							<li><a href="#" class="enclose">Why Partner with CSI?</a></li>
							<li><a href="#" class="enclose">Partner Profiles</a></li>
							<li><a href="#" class="enclose">FAQ</a></li>
							<li><a href="#" class="enclose">Send Me Information</a></li>
						</ul>
					</li>
				</ul>
			</div>
CSS:
Code:
body {
			background-color: #CCCCCC;
			padding: 0;
			margin: 0;
		}
		#top_nav_container {
			position: relative;
			z-index: 100;
			display: block;
			padding: 0;
		}
		#topnav, #topnav ul {
			padding: 0;
			margin: 0;
			list-style: none;
		}
		#topnav li:hover > ul {
			display:block; 
			position: absolute; 
			top:-11px; 
			left:80px; 
			padding: 10px 30px 30px 28px;
			width: 120px;
		}
		#topnav a, #topnav a:visited {
			font-family: Verdana, Arial, helvetica;
			display: block;
			font-size: 10px; 
			color: #387cae; 
			height: 25px; 
			line-height: 24px; 
			text-decoration: none;
			text-indent: 5px;  
		}
		#topnav a.enclose:hover {
			background-color: #387cae; 
			color:#FFF;
			padding: 0px;
		}
		#topnav a.drop:hover, #topnav a.drop:link {
			background-color: #FFFFFF;
			height: 34px;
		}
		#topnav a.enclose {
		border-bottom: 1px solid #FFFFFF;
		border-right: 1px solid #FFFFFF;
		border-left: 1px solid #FFFFFF;
		}
		#topnav .enclose {
			width: 120px;
			font-family: Verdana, Arial, helvetica;
			display:block;
			font-size: 10px; 
			color: #387cae; 
			height:25px; 
			line-height:24px; 
			text-decoration:none; 
		}
		#topnav li {
			float:left; background-color: #d4e6ef;
		}
		#topnav li:hover {
			position:relative;
		}
		#topnav li ul {
			display: none;
		}
		#topnav > li:hover > ul {
			left: -30px; 
			top: 24px;
		}
		.drop {
			background-color: #FFFFFF;
			float: left;
		}

I really appreciate any help you can give!

-Dan