You're welcome mate.
It's because the footer is inside the main container. If you want the footer inside the main container just put a DIV inside the main container before the footer with your main content inside it. Does that make sense?
Anyways I've created a quick example for you here to illustrate it better. Just view the source and lift the code if you need to.
http://andersbschjorring.com/Soeren/index.htm
The CSS is here..
http://andersbschjorring.com/Soeren/fumblies.css