My tired eys don't see the page looking odd in FF. However, I see you have no DOCTYPE. Google around, and learn bout that - it will affect how your page looks in various browsers.
Having looked at your page, I suggest you put
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
right at the top, before <html> in your page.
If you do that, then the charset needs to change form itf-8 to iso-8859-1.
Then check your page for validation errors.
Good night, and good luck.