Why doesn't my page display correctly in Internet Explorer?

[FallingReign]

Edit: There is a somewhat strange solution to this question. Check my answer posted belowI am working on this site and it works perfectly... Or at least, it did work perfectly until earlier today. I don't know what I did, I made some minor changes to the code but no changes to the front page. The site is tested to work correctly in FF and Chrome but of course it crashes in Internet Explorer.I have tried a lot of standard "troubleshooting techniques" like taking parts of the code and making it comments but nothing seems to be working.It should look like:

• The "content holder" should be surrounded by two green boxes and should be centered (Chrome and FF works)
• When you hover the tabs drop downs should appear (again, works in Chrome and FF)
• Just noticed the font actually changes in IE

My deadline is 18. September (this Saturday), so I would love quick answers. I think the problem might have something to do with my stylesheet since that is the only thing affecting the front page that I could've changed without thinking about it.Oh, and just to mention...A part of the site is build in PHP (which is why you can't see it) but it is mostly just "require/include", that I use.