If you’re talking about that blank box below your menu and above your content area, it looks like a widget. Do you have a widget set for the Above Content Area? Your source code shows some kind of ‘googletag’ javascript code, so I think that’s the issue. (It looks like it’s supposed to be a header script, but that’s only a guess, because I’m not familiar with it.)
I’d try moving the widget to the Inactive area (if there’s one there) and seeing if that gets rid of the box. At least then you’ll know whether that’s the cause.
*Note: I’m just another Parabola user, so I’m only speculating/trying to help.