I was using Dave Gandy's great Twitter Boostrap font library Font Awesome which provides a font stylesheet to make use 200+ icons on my project imnosy.com. All was going well and good in Chrome, but when I took a look in Firefox, this is what I saw:
In looks like the stylesheet wasn't implementing the font conversion from the character to the image. I stumbled on the Stack Overflow post "Firefox failing at fonts" which highlights that Firefox doesn't like hotlink/cross-domain requests for fonts. I was embedding the style sheet as follows:
The solution to this was to simply checkout the project, and embed the stylesheets inline as so:
Another one bites the dust :)