CSS Question - child nav links push over parent links

Hello!
I'm working on a quick web project for my brother and am having some noob CSS problems. When I add child pages to the navigation, they push over the rest of the main navigation. Not sure how to fix that. You can see what I mean at www.scottfairdosi.com/portfolio
The top (main) navigation bar has a huge break between PORTFOLIO and RESUMES because of the child pages.
Any help would be appreciated!