you need to convert the sublevel to use 1 LI tag, and have each link in the 1 li, add a width to the sublevel LI tag, and float the links to the left. for example:
<ul class="level-1">
<li><a href="#">Sub Item 1</a></li>
<li><a href="#">Sub Item 2</a></li>
<li><a href="#">Sub Item 3</a></li>
</ul>
to:
<ul class="level-1">
<li style="width:315px;"><a href="#" style="float:left;">Sub Item 1</a>
<a href="#" style="float:left;">Sub Item 2</a>
<a href="#" style="float:left;">Sub Item 3</a></li>
</ul>