Workaround Firefox/Iceweasel fontface issue
Due a very restrictiv »file uri origin«-policy Firefox/Iceweasel won’t load custom fonts.
Try to set a specific header for each font file (TTF, OTF, EOT) in your .htaccess:
<FilesMatch "\.(ttf|otf|eot)$">
<IfModule mod_headers.c>
Header set Access-Control-Allow-Origin "*"
</IfModule>
</FilesMatch>
(via)