Sidebar shifted down suddenly

Hi im in desperate need of help.

I’ve got my wordpress running and have been using mesozaic themes for 2 months – it has been great!

but suddenly today, i found that my sidebar shifted downwards. i have not altered / edited any part of the page since the last time it was ok (which was just a few hours before i found out the sidebar shifted downwards!). i tried switching themes but its the same for all themes. the sidebar dropped below the page – in both browsers IE and mozilla.

pls help – see the prob at https://alloveragain.net

??