Problems with PHP/CSS in IE but not Chrome

I recently split my HTML site in PHP so I can make global changes more开发者_StackOverflow中文版 easily and get ready for a possible migration to Wordpress. The HTML version works with IE and Chrome. Now that I split the site in PHP it only works in Chrome. In IE a lot of the CSS elemets are missing. Is this a common mistake I can fix? Remember the same HTML code works in IE so it has to be something I am doing wrong in the PHP version. I have the same issue with another website I am working on. Maybe there is a special character I am missing?

Website URL: http://dursoboxing.com/

Try getting rid of that comment right at the start. I think IE is a little shirty about having anything, even whitespace before the doctype declaration, and not having a doctype does much worse things to IE than it does to any other browser.

Maybe some unclosed HTML tags in partial views? Modern browsers are quite smart and try to predict which tags to close first and later on.