dropdown menu in IE7,8 needs fixin'

I've had lots of success in getting IE to play nice in the past, but I'm buffaloed here. The dropdown menu is visible and works, but it's having some margin/padding issues and no matter what kind of conditional statement or h开发者_如何转开发ack I try to employ, it won't straighten out.

Example page: www.erisdesigns.net

HTML (links removed so that I can post):

<div id="wrapper">
<div id="header">
    <ul id="nav">
    <dl class="dropdown">
      <dt id="one-ddheader" onmouseover="ddMenu('one',1)" onmouseout="ddMenu('one',-1)"></dt>
      <dd id="one-ddcontent" onmouseover="cancelHide('one')" onmouseout="ddMenu('one',-1)">
        <ul>
          <li></li>
          <li></li>
          <li></li>
        </ul>
      </dd>
    </dl>
    <dl class="dropdown">
     <dt id="two-ddheader" onmouseover="ddMenu('two',1)" onmouseout="ddMenu('two',-1)"></dt>
      <dd id="two-ddcontent" onmouseover="cancelHide('two')" onmouseout="ddMenu('two',-1)">
        <ul>
          <li></li>
          <li></li>
          <li></li>
        </ul>
      </dd>
   </dl>         
  </ul>
  </div>

CSS:

#nav {
    top:80px;
    width:65%;
    margin-left:600px;
    padding:0;
    background:#999;
    text-align:center;
    list-style:none;
    position:relative;
    z-index:3;
}

.dropdown {float:left; text-align:center; font-size:14px; padding-right:5px; color:#FFF;}
.dropdown dt {width:175px; padding:8px; font-weight:bold; cursor:pointer; background:transparent;}
.dropdown dt:hover {background:transparent; color:#000;}
.dropdown dd {position:absolute; width:175px; display:none; background:transparent; z-index:200; opacity:0;}
.dropdown ul {width:175px; margin-top:23px; list-style:none;}
.dropdown li {display:inline-block; margin-left:-108px; float:left; padding-left:35px; text-align:left;}
.dropdown a, .dropdown a:active, .dropdown a:visited {display:inline-block; padding:5px 0px 10px 15px; color:#CCC; text-decoration:none; background:#999; width:175px; float:left;}
.dropdown a:hover {background:#999; color:#000;}
.dropdown a.menu {background:transparent; width:200px; float:left; text-align:left; color:#FFF;}
.dropdown a.menu:hover {color:#000}

Imo too much markup. Try replacing <ul id="nav"> with <div id="nav"> since you are not wrapping anything with <li></li> so IE might have some problem with that.