Is there a way to keep the menu bar from scrolling with the rest of the page?

Hello all,

I am curious if there is a way to keep the menu bar at the top of the screen as the page scrolls below it.

I have Atahualpa set up at www.sketchklubb.com/main

Most of the pages are fine except for the blog. As you scroll down to view the posts, the menu bar dissappears.

Any help is appreciated.

Thank you for your time,
Nick