I have taken a look at the page and it appears about the same in FireFox and IE except for IE6. In this browser it seems that the content on the page is appearing below the left and right columns content.
In my testing I discovered that the width of the image you are using is causing this problem:
<img src="img/freesat/freesat_header.jpg" alt="Freesat - Experience the brilliance of digital TV ...subscription free" />
The image is currently 500px wide. If you update this to be 490px wide it fits and allows the content to sit nicely.