Yeah, it's a window-size issue. Your site is set to full width and expands with a wider window, but unfortunately doesn't have a minimum width so a narrower screen resolution makes everything wrap. In fact, the division for your content is called "wrap". Go figure. If you look at the layout code, it's a mess. Sorry. There is actually a separate page dropped into the main page, not by using a frame but rather inside a division. It even includes an additional <head> and <body> area and it's own css file.
Could definitely do with a bit of tidying up.