The problem is one of math. You cannot divide 1000 by 7 and get a round number. because of this, you will not be create a menu layout that spans the entire width.
Right now you have the menu outside of the top nav:
<ul class="level-0" id="cssmw">
<li><a href="index.html">Home Page</a></li>
<li class="parent"><a href="schedule.html">Schedule</a>
<ul class="level-1">
<li><a href="schedule.html">ISSW Schedule</a></li>
<li><a href="activities.html">Activities</a></li>
</ul>
</li>
<li><a href="papers.html">Papers & Posters</a></li>
<li><a href="info.html">Area Info</a></li>
<li class="parent"><a href="lodging.html">Lodging & Travel</a>
<ul class="level-1">
<li><a href="#">Resort at Squaw Creek</a></li>
<li><a href="travel.html">Travel Resources</a></li>
</ul>
</li>
<li><a href="sponsors.html">Exhibitors</a></li>
<li><a href="contact.html">Contact</a></li>
</ul>
<script type="text/javascript">if(window.attachEvent) { window.attachEvent("onload", function() { cssmw.intializeMenu('cssmw',{select_current: 0, orientation: 1}); }); } else if(window.addEventListener) { window.addEventListener("load", function() { cssmw.intializeMenu('cssmw',{select_current: 0, orientation: 1}); }, true); }</script>
<div id="topnav"></div>
If you place the menu inside the topnav div:
<div id="topnav">
<ul class="level-0" id="cssmw">
<li><a href="index.html">Home Page</a></li>
<li class="parent"><a href="schedule.html">Schedule</a>
<ul class="level-1">
<li><a href="schedule.html">ISSW Schedule</a></li>
<li><a href="activities.html">Activities</a></li>
</ul>
</li>
<li><a href="papers.html">Papers & Posters</a></li>
<li><a href="info.html">Area Info</a></li>
<li class="parent"><a href="lodging.html">Lodging & Travel</a>
<ul class="level-1">
<li><a href="#">Resort at Squaw Creek</a></li>
<li><a href="travel.html">Travel Resources</a></li>
</ul>
</li>
<li><a href="sponsors.html">Exhibitors</a></li>
<li><a href="contact.html">Contact</a></li>
</ul>
<script type="text/javascript">if(window.attachEvent) { window.attachEvent("onload", function() { cssmw.intializeMenu('cssmw',{select_current: 0, orientation: 1}); }); } else if(window.addEventListener) { window.addEventListener("load", function() { cssmw.intializeMenu('cssmw',{select_current: 0, orientation: 1}); }, true); }</script>
</div>
then add:
width:994px;
margin: 0 auto;
to the topnav css selector, it will center the menu in the topnav div.