FireFox align problem.

[DoubleJ]

I have my menu with button rollovers working now via my css.
But now an other problem occured while viewing my design in several browsers.
Opera and Internet Explorer align the navbar where it should be while in fire fox the navbar is moved a little to the right which makes my page look like crap.

How can I make it so that Fire Fox also aligns my page right in Fire fox?
http://dev.doublejweb.net/doublejweb/index.html
is my work in progress page with the bug
http://dev.doublejweb.net/doublejweb/doublejweb.css
is the stylesheet.

[BonRouge]

ul, li {
margin:0; padding:0;
}

[DoubleJ]

Thanks again.
I had rewritten it from scratch again but I couldn't find the problem.
so thank you for your help.