IE Adds Padding

I'm working on a three column layout with rounded corners at top and bottom. IE is adding padding to the MainContent div but Safari and Firefox are not. I've added background images in divs at the top of each column. I know that IE includes padding and borders in widths, but I'm not using those in the left or right sidebar. I've set padding to 0 and tried playing with widths, but nothing seems to affect IE's display...

Here's my HTML page:
http://www.sciencemadefun.net/www3/index2v1.cfm

And here's my style sheet:
http://www.sciencemadefun.net/www3/style2v1.css

Any help is greatly appreciated!
:eek:

Have you tried a global reset?

* {margin:0; padding:0; border:0;}