three column fixed layout and text-wrap

I have a page using the two col fixed header and footer layout.
I know that if your #maincontent div has a left margin the width+ of the
sidebar, the sidebar appears to continue down the page no matter how much
content is has in it. In the 2 column fixed layout comments it says to delete
that margin if you want the text to flow into that space after the sidebar
content ends. This is what I want but it does not work in IE 7.

Is there a workaround? :sad;