Grid Theme Responsive (by Dessign) mobile problems

Hello!

I use the free Grid Theme Responsive by Dessign.net. Could anyone say why the site doesn’t work properly on mobile although the theme is responsive? I’m using Nokia Lumia 620 and IE and there I can only see the photos from the homepage. I cannot see menus. What could be the problem?

My site can be found from satumaa.net.

Thanks in advance!