Coding problem, Sidebar below posts

Look where? Need a link, please :)!

Sidebar is okay in Firefox, but you have many mark-up errors on your page which may be causing the problem in other browsers:

http://validator.w3.org/check?uri=http%3A%2F%2Fwww.itsoverflowing.com%2F&charset=%28detect+automatically%29&doctype=Inline&group=0

The page also takes a really long time to finish loading — maybe try a caching plug-in after you’ve dealt with all the errors.

EDIT: I guess someone else already addressed these a while back:
http://wordpress.org/support/topic/sidebar-below-posts-help?replies=2