For your right bar, google for "clear floats". IE expands floats to the bottom of the box which is incorrect. FF won't, and it shouldn't, so you need to clear the float.
Check your widths. IE tends to screw up page widths so if your total width is, say 800px, and your divs add up to 800px, IE will drop that right bar down thinking there's no room for it. Just set all your margins and paddings to zero in the body. Then make them what you want throughout the code so all browsers will follow the same rules and not make some up like IE does.
In your CSS, you have the element 'Body'. Make that all lower case.