Incorrect formatting in Firefox 3.0.19

I have nearly finished my website, but I am having some strange formatting issues in Firefox. In all my other browser tests, everything looks fine.

In Firefox 3.0.19, everything looks fine apart from the header on one page.

In any other browser, the page looks like this:

In firefox, the page looks like this:

I think the issue is probably a CSS conflict, as I basically had to re-skin and existing php script (OSTicket) to match my site. I had hoped my CSS file and the CSS files belonging to OSTicket could live in harmony, but apparently not.

What is strange is that the entire header is simply this:

<div id="topPanel"> 
<ul> 
 
<li><a href="http://www.sitepoint.com/forums/faq.html">FAQ</a></li> 
<li class="active">Free Advice</li> 
<li><a href="http://www.sitepoint.com/forums/guide.html">The Guide</a></li> 
<li><a href="http://www.sitepoint.com/forums/">Home</a></li> 
 
</ul> 
 
<a href="http://www.sitepoint.com/forums/index.html">img src="../images/mainhead.jpg" title="The School Appeals Guide" alt="..." border="0" /></a> 
  
</div>  

There really is no clever formatting. It is basically a centered image with no “class=” value. If anyone can work out what is causing this, it would be much appreciated.

The URL for the offending page is: here

Remove position:absolute from #topPanel img and #topPanel ul. They don’t make any sense and they are causing that problem.

Many thanks - fixed it. This website is a bit of a frankenstein creation, and there is a lot of redundant coding I need to get rid off.