Hello all! Not sure if this is a common problem, but allow me to try to explain.

When I view my site in FF,  there appears to be added spacing to the right of each menu item. The spacing is substantial enough to expand the menu bar, and push it out of the design. When I click a link or reload the page however, the spacing goes back to normal and looks perfectly fine. When I clear the cache and reload the page, the problem returns. This problem only occurs in FF, in IE it works perfectly. Is this a skin or css issue? I will post my css code if needed, just let me know.

Link to site: http://www.manolisestates.com

Thanks in advance for your help :)

Still isn't fixed :( Any more suggestions?

Using dnnMENU or SolPartMenu doesn't have anything to do with the spacing. What we need to do is face the problem and find the solution for it. NONE of the current core navigation webcontrols in DNN supports list item navigation.