This is NUTS….CSS Issue

Hi guys. I havent a clue whats happening here. I have set up a new blog at http://www.excellenceforall.co.uk/blog/. It works fine in Firefox and Safari but in IE7 there is a problem.

In IE7 when the page loads there is a large gap between the masthead and the main content. If you put your mouse over the side bar links the gap dissapears but then when you mouse over the page links at the top of the page the gap re-appears.

Its mind boggling.

Any help would be great.