WIP- Help with CSS and Javascript please

Could someone on a Windows machine take a look at this test site of mine?

http://justmytypegraphicdesign.com/test2a.html

Then, if the menus are not all on one line in your browser, look at the source and see if you can tell me why?

I get it to work perfectly on my Mac with Safari, Explorer, Camino and Firefox but when I was able to try it on a friends PC using Explorer the menu didn’t line up anymore.

I’m lost.

-I should add, if it does work, I must have fixed it. In that I can’t get to a Windows machine now I wouldn’t know. :ponder: