Drop Down Menu problems with Internet Explorer

I’m sorry to ask again but I still don’t know what to do. My style sheet for navigation is as such:

#navigation
{
	position:relative;
	clear:both;
	float:left;
	width:960px;
	margin:0 0 10px 0;
	padding:10px 10px 0 10px;
	background:url(images/navigation.png) top left;
	list-style:none;

	/*position:absolute;
	bottom:10px;
	right:0px;*/
}

#navigation li
{
	position:relative;
	float:left;
	margin:0;
	padding:0;
	width:auto;
}

#navigation li ul
{
	z-index:10;
	position:absolute;
	top:31px;
	left:-9999px;
	float:right;
	margin:0;
	padding:0;
	list-style:none;
	background:url(images/navigation_sub.png) top left;
}

#navigation li:hover ul
{
	left:0px;
}

#navigation li ul li, #navigation li ul li ul li
{
	float:left;
	width:200px;
	position: relative;
}

#navigation li a
{
	display: block;
	float:left;
	padding:8px 10px;
	font-weight:bold;
	text-transform:uppercase;
	color:#FFF;
}

#navigation li ul li a
{
	width:170px;
	margin:5px;
}

#navigation li ul li a:hover
{
	background:url(images/navigation.png) top left;
}

#navigation li ul li:hover
{
	background:none;
}

#navigation li:hover, #navigation li.current_page_item, #navigation li.current_page_ancestor
{
	background:url(images/navigation.png) top left;
}

#navigation li ul li ul, #navigation li:hover ul li ul
{
	top:0px;
	left:-9999px;
}

#navigation li ul li:hover ul
{
	left:200px;
}

#navigation li.rss
{
	float:right;
}

and the fix for ie7 looks like this

.ie7 #header { z-index:5; }
.ie7 #navigation { float:none; }

But the menu is still showing up as a list as opposed to a dropdown menu. I’ve searched everywhere and can’t find anything to help. Any ideas would be greatly greatly appreciated!!! Thank you!!