Sounds like you may have had an evil empire auto update in IE that changed some settings.
The first thing to try is to complete delete all the files in your Temporary internet folders and cache folders. Delete all cookies. Do that through the Internet Options in the control panel.
I use Foxfire and use an add-on called IE Tab. This helps load pages that work in IE but not as well in FoxFire.
https://addons.mozilla.org/en-US/firefox/addon/1419
Try the above link to the add on. When it's loaded and you have trouble with a site, you go to tools, ie tab, and then add that site to your list.
See if that helps you.
Oh, and ignore what ever any of the Mac Heads say. They can't help you. They'll only try to sound superior like they drive a Mercedes or something.