CSS Div Height Problem, Help Please!

I have to main divs (container and middle column) where middle column is nested inside of container. I’m trying to keep their heights at 100% all the time, but to also adjust their heights based on the height/amount of content inside of middle column. I’m having different issues in Firefox and IE. The URL is www.pearsonportfolio.com and the css url is www.pearsonportfolio.com/stylesheet.css. Any help would be appreciated. Thanks!

JPearson311