ie7 and ie8 ignore "margin:0px auto;"
Your page is rendering in Quirks Mode in IE because you have a comment:
<!--HOSTURL:blog.helpcurenow.org--><!--HOSTURL:blog.helpcurenow.org-->before the <!DOCTYPE ...>. The DOCTYPE needs to be the first thing in the document, or IE will ignore it.
If you remove that comment, or move it after the DOCTYPE, it works perfectly.
Get rid of the "<!--HOSTURL:blog.helpcurenow.org--><!--HOSTURL:blog.helpcurenow.org-->" comment at the top. The doctype needs to be the first thing after the HTTP headers, or IE goes into quirks mode (and doesn't understand the "margin: auto" jazz).
RichieHindle - Thanks so much ! I was adding a static home page to my site and made the mistake of linking to my custom stylesheet before the get_header() call ! This obviously caused exactly the problem you described. Spent 2 or 3 hours on this before I saw your post.
Thanks again !