Small Navigation Glitch Is Driving Me Crazy, Please Help

Hello,
I've been working on a website at http://www.boxofvomit.com
The navigation bar on top (is sticky also) contains links to anchor's on the page.

The problem I'm having is that when you click a link it "drops" down in the navigation bar and pushes the other icons up. WHY?
I'm been trying all sorts of things for the last few days and I can't seem to figure out what is causing this. They should stay uniformed, scaled when hovered, but uniformed when clicked.
Any help is greatly appreciated and will save my sanity! Can I just pay to have some help with this?
Thank you.

 

I see that after click on the anchor link the whole navigation bar disappears for a moment and then shows again. This is because the navigation bar on top is not sticky all the time. If you use JS plugin for the sticky bar, take a look if there is some param about offset or something. Maybe I can help but need more info about themes and plugins used here.

 

Well, this does not happen on Firefox on OSX - so you need to be more specific about what browser you're using, and such. It also seem to be working fine in Chrome for OSX, so again, a bit more info would help.