Cannot Get Drop Down Menu to work

I have taken over a website that was already up and running and from what I can tell they where using WordPress Menus. I needed to add a couple of custom menus to the main navigation which include two drop down menu items. I have them set up in menus correctly but I am thinking there has to be something that needs to be changed in the stylesheet, header.pho or functions.php. Here is what the stylesheet looks like:

body.page nav.menu-main-menu-container, body.blog nav.menu-main-menu-container, body.single nav.menu-main-menu-container {
width: 770px;
position: absolute;
top: 39px;
left: 115px;
}

body.home nav.menu-main-menu-container {
width: 770px;
position: absolute;
top: 39px;
left: 180px;
}

ul.menu {
height: 2.375em;
}

ul.menu li {
float: left;
border-right: 1px solid #6e7692;
position: relative;
}

ul.menu li ul.sub-menu {
position: absolute;
left: -999em;
}

ul.menu li a {
display: block;
padding: .5625em 1em;
font-family: ‘league-gothic’;
font-weight: normal;
color: #f59213;
font-size: 1.10em;
text-shadow: 2px 2px #000;
text-decoration: none;
text-transform: uppercase;
letter-spacing: 1px;
}

ul.menu li:hover {
background: transparent url(‘images/active_bg.png’) center top no-repeat;
}

Any help with this would be greatly appreciated!

Wesley