Ah, I know what's causing that. If you are using Firefox, you have a really old version, just so you know.
Anyway, I was using a modern web technology thing, which isn't supported in old browsers and IE, and I've just added a library that implements it, so could you check if it works now.
... You should really update your system when you can. If only for the security things... It isn't like Skype where newer versions are universally crap.