Webfont not loading only in IE11, Windows 8.1 version

Hello, I have a problem with this website and I'm at a total loss:

http://www.cirworld.eu

Aside from some quirks, it's working fine on all browsers, except IE11 on W8.1.

The problem is with webfonts. They just won't load with that browser/OS combination.

The site is built with Wordpress and a theme I heavily modified.

The css for the webfonts was originally:

@import url(http://fonts.googleapis.com/css?family=Open+Sans:400,300italic,300,400italic,600,600italic,700,700italic,800,800italic);
font-family: 'Open Sans', sans-serif;
@import url(http://fonts.googleapis.com/css?family=Philosopher:400,400italic,700,700italic);
font-family: 'Philosopher', sans-serif;

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at the beginning of the style.css file.

I changed this to:

@font-face {
		font-family: 'Philosopher';
		src: url('fonts/gabriola.eot');
		src: url('fonts/gabriola.eot?#iefix') format('embedded-opentype'),
				 url('fonts/gabriola.woff') format('woff'),
				 url('fonts/gabriola.ttf') format('truetype'),
				 url('fonts/gabriola.svg#gabriola') format('svg');
		font-weight: normal;
		font-style: normal;
		}

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I wanted to use this gabriola font I bought but I kept the name Philosopher to avoid changing too many lines of code.

Anyway, my webfont doesn't show up in IE11/W8.1.

Google fonts didn't show up either (not even in IE11/W7, actually), until I added this to the header of the theme:

<link href='http://fonts.googleapis.com/css?family=Open+Sans' rel='stylesheet' type='text/css'>

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I hope someone can help me because I don't know how I may add this web font in a way that IE11/W8.1 recognizes it too...