Kubrick Firefox = problems for me

Hello,

I can’t find a definitive answer for this problem: My blog was created using the default Kubrick theme. It looks great in IE. In Firefox, all pages, including the home page, stop short somewhere down the page. The Footer stops there too. But my text and content keep on going over the dark background of the blog body. It’s like the page is not reading how long it needs to be.

Thanks in advance for any suggestions