There are an awful lot of styles being applied that are not defined in the css templates. I am looking at the source of the menu, and everything from width to z-index looks like it is being called directly on the page. That might be the source of the problem.
See here:
Code:
<div id="TransMenu16" class="transMenu top" style="width: 189px; height: 41px; left: 774px; top: 240px; z-index: 123; visibility: hidden; "><div class="content" style="width: 187px; height: 39px; top: -39px; ">
And here is another css file:
<link rel="stylesheet" type="text/css" href="css/transmenu.css" />