CSS Appearing in posts; blog not showing properly in IE

my company runs several blogs. On https://design-bitch.com we’ve been experiencing a weird problem where a bunch of CSS was appearing in posts. This, in turn, was causing the rest of the page to malfunction. No more than one page of the blog was showing. The original theme we were using was “Neoclassical 1.1”, and removed the CSS from the posts. I swapped it out for “WordPress Default 1.6” which seemed to fix the missing content issue. However, in IE and Chrome, the first page of posts isn’t showing up correctly. It all looks fine in Firefox. Anyone have any idea what might be going on? I can include the CSS from the posts if you need it.

Thanks