CSS horizontal navigation with UL working until I add subnav.. now it moves the nav next to it when the dropwdown happens

Question

I have a problem with the dropdown (ul li ul) pushing the navigation thats to the right over when I add the subnav.

To view: http://newenergycities.org/header2.html

I tried to add a special class to the nav item to the right, but I don't think I've got the right idea. Any (right) ideas would be greatly appreciated!