Twenty eleven side bar problems please help

I’ve searched the forum for a solution, but haven’t found an answer yet.

I’m using a twenty eleven child theme. I’ve added a sidebar to the single page view. I’m currently using the “twenty eleven extensions plugin” to achieve this, but have tried at least 3 other methods and they all push that the sidebar to the bottom in IE7, I know old browser, (NOTE: I haven’t tested in other explorers so would be cool to know how they render).

The sidebar seems to display fine in chrome, firefox, opera and safari. Can anyone help suggest how to go abouting fixing this explorer problem. Heres a link to a single page…

http://pssms.com/summers-war.html

Thanks for you help

tigs x