IE jacking up design (again)

Ok. So I came up with a new layout, and once again everything is working splendid in FF, but IE is adding 40px to the rap (I measured it in an image editor) which is pushing the menu on the right out of the box and down below. I edited it for demonstration purposes so it appears almost as it should in IE, but the menu is cut off in both FF and IE.
Any ideas as to where it’s getting the additional 40px? The content div should only have a left margin of 40px, not 80px like IE is doing.
https://tekmonki.com/wpindex.php