Issues with layout (possible proxy issue)

I have recently finished making an intranet page for the school I work at, the main aim of it being to speed up the time it takes students to get to the sites they use often. However, whenever we try to go to the intranet page on the domain computers (that are behind a proxy), the layout changes to being only one column and the symbols over the logo thumbnails don’t display correctly. The theme I am using is Gridster-lite.