IE8 issues

Hi, I'm having some compatibility issues with IE8; the main text area is not displaying at all in many of the pages of my site, especially the news pages. It's at www.ncmh.info All works fine in up to date browsers, however, I know that a fairly significant number of our users are going to be stuck with older machines, so I can't afford to ignore them. Any ideas what is causing this? Oddly, it seems to have gotten worse recently. Thanks, Lee