Odd Bug showing in Firefox

Site is here http://topments.com. In IE the white links in the blue header menu bar show up fine. In firefox though everything besides the first Home link jumps down a notch to the white content area, where you need to highlight everything to see it. Anyone have any idea why this is happening?

 

change the 'display:inline;' that you have on the <li> items to: 'float:left' and it works fine