I'd be grateful if someon could take a quick look at this: http://www.fightforsight.org.uk/sightlosspsp

It's a bit of a mess, as work in progress. But What is is: there is a space at the top of the page, and I cannot figure out why. The body has been set to 0 margins and padding. The Header DIV should really be positioned at the top of the page. I just cannot work out why it isn't.

Can somebody spot what's going on here?

Many thanks.