Back to your question, its not possible to make the nav bar normal it was designed like this. and i cant simply post you some css to make the navbar normal and mess with the header just because when auto scrolled to a topic the navbar covers the top of the topic by 64 pixels just do a quick scroll up man no big deal to me, really
BUT just a heads up, I will update this theme after ips 4.2 release, it will be much more advanced dozen of more settings and more features like a fixed sidebar widget and news ticker bar and complete color customizer