Not sure how to fix IE display problems, please help.

[msclala]

Hi. I am new to css-only design. I am having trouble getting my site to display properly in IE. The main content drops below my right column float. I know the issue lies with the box-model, but I can't figure it out. I would appreciate any help with my code. Thank you for your time.

http://www.cloudart.com

http://www.cloudart.com/cloudart.css