Menu problem

Alright, I am working on a site, and the menu bar will not display correctly in ie. It is going vertical, and it needs to be (obviously) horizontal.

Here is the css.

#nav {
	float: left;
	margin-top: -20px;
	height: 20px;
}

#nav li {
	display: inline;
	color: #777777;
	margin-left: 5px;
	margin-top: 5px;
	margin-right: 5px;
	font-size: 26px;
	line-height: 26px;
	margin-bottom: -20px;
	padding: 5px;
}
.active_category {
	color: #000000;
	background-color:#ffffff;
	padding: 5px;
	margin-left: -5px;
	font-weight: bold;
	}
.active_category:hover {
	color: #777777;
	}

.current_page_item a{
	color: #000000;
	background-color:#ffffff;
	padding: 5px;
	margin-left: -5px;
	font-weight: bold;
	}
.current_page_item a:hover {
	color: #777777;
	}

And the html/php:

<div id="nav" class="clear">
			<ul>
				<!-- home for headernav <li <?php if (is_home()){echo 'class="current_page_item"';}?>><a href="<?php bloginfo('url'); ?>/">Home</a></li> -->
				<?php wp_list_pages('title_li='); ?>
			</ul>
			</div>

Thank you for your help.