Firefox has an extremely tight Cross-Domain policy. This includes sub-domains of your site (even www).
In your css you reference the fonts with http://jamhouse.com.au/templates/gk_fest/js/html5/font/vjs.XYZ (notice no www.) while on the link you posted it is http://www.jamhouse.com.au If you goto just http://jamhouse.com.au your fonts work.
You have a few options:
Recommended for true cross domain
Either set up an Access-Control-Allow-Origin in your .htaccess or httpd.con
For Apache: http://davidwalsh.name/cdn-fonts
For IIS: http://deserialized.com/iis/serving-web-fonts-cross-domain-with-iis/
-- OR --
Recommended for your case
you can reference the fonts relatively with url(font/vjs.XYZ)... as this will use whichever domain/sub-domain you are on (www or non-www)
-- OR --
You can enforce either http://www.jamhouse.com.au or http://jamhouse.com.au and reference the fonts with whichever way you choose.
For Apache: http://www.thesitewizard.com/apache/redirect-domain-www-subdomain.shtml
For IIS: http://forums.iis.net/t/1154053.aspx/1
-- OR --
You can embed the fonts directly in the css (which I've opted for my video.js installations)
Embedding fonts in css - http://blog.patdavid.net/2012/08/embedding-fonts-with-css-and-base64.html
Under expert mode you can choose base64 Encoded. http://www.fontsquirrel.com/tools/webfont-generator (I had limited success with their encoding, the play triangle (\e001) was not showing up.)
Encoding files in base64 http://www.motobit.com/util/base64-decoder-encoder.asp (make sure the output is all on one line with