Help with Sidebar layout in IE

Hi there,
I am trying to set up the sidebar to be flush with both header and right background color. When it was looking great in ALL browsers but IE, the ‘margin-left’ setting was at 650px. However, in IE on a PC (IE 8), the sidebar floated down about 500 px and there was white space between header and sidebar.

So, when I changed to 647px margin-left, looks great in IE, but now has a white bar on the right of sidebar in all other browsers. Is there any way to get it to be positioned correctly in both??

https://professionalliabilitylawblog.com/blog/

Thank you!!

Designteam