Ive tried to implement font-awesome icons into my main menu, and use a plugin that also utilizes font-awesome icons.
My issue is that the icons work fine in Chrome and IE, but they do not show in Firefox at all.
I have looked for a solution, the common fix did not work for me:
<FilesMatch ".(ttf|otf|eot|woff)$">
<IfModule mod_headers.c>
Header set Access-Control-Allow-Origin "*"
</IfModule>
</FilesMatch>
Here is how the icon looks in firefox:
http://gyazo.com/c912fd997ccd70cb6b499696d8d49dda
I am currently using the Font-Awesome 4 Menus Plugin
http://wordpress.org/plugins/font-awesome-4-menus/
The code I am inserting to get the icon to show is:
<i class="fa fa-download fa-1x" style="color: #ff6600;"></i>
if u added wp_head() in your header please remove it and try again. this helps me . after removing that i got the icons working in firefox also. please note remove only wp_head() do not remove wp_footer() from footer.php.