Js O1 menu not working in IE

I kinda thought this might come back to haunt me. I have an older 3.0.1 WP site with theme Js O1. The menu is an inline-block drop down – and it works fine in all non IE browsers, but for some reason you can’t access the child list elements in IE.

site: https://www.hospiceball.com

HTML, CSS:

<ul>
    <?php wp_list_pages('sort_column=menu_order&sort_order=desc&title_li=&depth=2&')?>
</ul>

#navigation{
	background:#bd8ed8;
	font-family: 'Lucida Grande', Geneva, Arial, Verdana, sans-serif;
	margin: -10px auto 0;
	border-top:2px solid #a201ff;
	border-bottom:2px solid #a201ff;
	float:left;
	width: 800px;
	display: block;
	width: 100%;
}

#navigation li{
	list-style:none;
	float:left;
}

#navigation li a{
	display:block;
	padding:0 8px;
	color:#FFF;
}

#navigation li a:hover{
	color:#000;
}

#navigation li ul{
	display: none;
}

#navigation li:hover ul, #navigation li.hover ul {
	position:absolute;
	display:inline-block;
}

#navigation li:hover li, #navigation li.hover li {
	float:left;
}

#navigation li:hover li a, #navigation li.hover li a {
	color:#000;
}

#navigation li li a:hover {
	color: #357;
}