Can't see CSS menu in Internet Explorer 8 (potential javascript issue?)

I keep getting complaints about this menu bar not functioning correctly in Internet Explorer 8. I have absolutely NO CLUE what is wrong with this code since it works on all other browsers, as well as earlier versions of IE.

Here is the website:

http://www.iirusa.com/centrallab

You can see the CSS here: http://www.iirusa.com/ed/4999/css/main.css

And here is my code for the menu:

    <script src="/upload/wysiwyg/AC_RunActiveContent.js" type="text/javascript>
    </script>
    <DIV id="header"><a href="/centrallab/home-page.xml"><img src="http://www.iirusa.com/upload/wysiwyg/2011-P-Div/P1625/P1625_Central_Labs_East.jpg" alt="Central Labs East" width="930" height="206" border="0" /></a></DIV>
    <DIV id="container">
    <ul id="nav">
    <li style="background: url(http://www.iirusa.com/upload/wysiwyg/2011-P-Div/P1625/P1625_menu_item_image.gif) no-repeat right center;"><a href="/centrallab/home-page.xml" title="HOME">HOME</a></li>
    <li style="background: url(http://www.iirusa.com/upload/wysiwyg/2011-P-Div/P1625/P1625_menu_item_image.gif) no-repeat right center;"><a href="#">EVENT DETAILS</a> 
    <ul>
        <li><a href="/centrallab/agenda-page.xml" title="Agenda At A Glance">Agenda At A Glance</a></li>
        <li><a href="/centrallab/workshop-page.xml" title="Monday Sessions">Monday Sessions</a></li>
        <li><a href="/centrallab/oncology-page.xml" title="Oncology Summit">Oncology Summit</a></li>
        <li><a href="/centrallab/speakers.xml" title="Speakers">Speakers</a></li>
        <li><a href="/centrallab/Whowillyoumeet.xml" title="Who You Will Meet">Who You Will Meet</a></li>
        <li><a href="/centrallab/attendees-page.xml" title="Attendees List">Attendees List</a></li>
        <li><a href="/centrallab/pricing-venue.xml" title="Pricing & Venue">Pricing & Venue</a></li>
    </ul>
    </li>

    <li style="background: url(http://www.iirusa.com/upload/wysiwyg/2011-P-Div/P1625/P1625_menu_item_image.gif) no-repeat right center;"><a href="#">PARTNERS</a> 
     <ul>
        <li><a href="/centrallab/sponsors-page.xml" title="Sponsors">Sponsors</a></li>
        <li><a href="/centrallab/exhibitors.xml" title="Exhibitors">Exhibitors</a></li>
        <li><a href="/centrallab/become-a-sponsor.xml" title="Become a Sponsor">Become a Sponsor </a></li>
        <li><a href="/centrallab/become-a-exhibitors.xml" title="Become an Exhibitor">Become an Exhibitor </a></li>
        <li><a href="/centrallab/become-a-media-partner.xml" title="Become a Media Partner">Become a Media Partner</a></li>
   </ul>
   </li>
 <li style="background: url(http://www.iirusa.com/upload/wysiwyg/2011-P-Div/P1625/P1625_menu_item_image.gif) no-repeat right center;"><a href="/centrallab/brochure-download.xml" title="Brochure">BROCHURE</a> </li>
 <li style="background: url(http://www.iirusa.com/upload/wysiwyg/2011-P-Div/P1625/P1625_menu_item_image.gif) no-repeat right center;"><a href="">REGISTRATION </a>
    <ul><li><a href="/centrallab/registration-LP.xml" title="Register">REGISTER </a></li>
      <li><a href="/centrallab/pricing-venue.xml" title="Pricing & Venue">Pricing & Venue</a></li>
      </ul></li>
      <li style="background: url(http://www.iirusa.com/upload/wysiwyg/2011-P-Div/P1625/P1625_menu_item_image.gif) no-repeat right center;"><a href="#">CONNECT</a>
      <ul>
      <li><a href="/centrallab/contact-page.xml" title="Contact Us">Contact Us</a></li>
      <li><a href="/centrallab/opt-in-page.xml" title="Opt-in">Opt-in</a></li>
      <li><a href="/centrallab/send_to_friend.xml" title="Send to a Friend">Send to a Friend</a开发者_C百科></li>
      <li><a href="http://www.linkedin.com/groupRegistration?gid=151146&amp;goback=.gdr_1219853769141_1.anb_151146_*2" title="LinkedIn" target="_blank">LinkedIn</a></li>
     <li><a href="http://partnershipswithcros.blogspot.com/" title="Blog" target="_blank">Blog</a></li>
     <li><a href="http://twitter.com/partnershipcros?utm_source=sidebar&amp;utm_medium=croshomepage&amp;utm_term=croshomepage&amp;utm_content=followcros&amp;utm_campaign=homepage" title="Twitter" target="_blank">Twitter</a></li>
     <li><a href="http://labroots.com/?appinstanceid=groups&amp;action=view&amp;id=150" title="Labroots" target="_blank">Labroots</a></li>
    </ul></li>
   </ul>
 </DIV>

The only other issue I can think of is that there is something wrong with the JS we are referencing which can be found here: http://www.iirusa.com/upload/wysiwyg/AC_RunActiveContent.js

Please let me know if you can help! Would be very appreciated and would make hours of frustration worth it!!

Its IE6 not IE8. The problem is that IE6 does not support the :hover selector on anything besides and a tag

On my IE8 installation your website doesn't work if IE8 is in Compatibility View.

Make sure that the browser does not go into the Compatibility View by adding this to your head:

<meta http-equiv="X-UA-Compatible" content="IE=edge">

Menus work perfectly when IE8 is not in CV.