Css Broken On Some Browsers After Move From Local To Web

I moved my CS-Cart from my local PC to a dev folder on our website today and it seems to have broken a bunch of my CSS.

The issue is, the site works almost fine from my browser, but another co-worker is missing some images and CSS (using IE).

I have tested on all browsers and its seems fine for me and another employee, but another employee is missing some images and CSS only on Internet Explorer.

Any ideas?

It seems that some CSS is not working in IE9. What can I do about this?