Right hand colum moved to bottom (css/html??)

Hey,

I have just encountered a problem with my template (it was all fine before) the right hand column ie, the pages, links, categories, etc. – has been bumped down to the bottom of the page, under all the content.

I have no clue why it has done so & any help someone could give me on it I would be greatly appreciated!

http://www.prettytime.net

Thank you for your help