By default at least IE up to 9 8 (not tested on IE10 IE 9 and 10 doesn’t block loading content and they use local fonts, if available) blocks loading page until fonts are not downloaded. Moving fonts for font-face to separate subdomain (eg. fonts.example.com) means that page loading will not be blocked by loading fonts from font-face. However, you may discover that fonts are not loaded after moving them to separate subdomain. What is wrong?

You must add header Access-Control-Allow-Origin "*" (or specify here your subdomain) when serve fonts from server to allow download and use fonts by browser.

Example rules for Apache:

<FilesMatch "\.(ttf|otf|eot)$">
<IfModule mod_headers.c>
    Header set Access-Control-Allow-Origin "*"
</IfModule>
</FilesMatch>