Facebook chat won't load?

[[♥]weeble[♥]]

I recently got a new "dongle" for my laptop and since having it I have not been able to use facebook chat. It comes up with the box in the side and I still get updates as to what people are doing, however it just says my contacts are "loading" however I don't see anyone and when I try and search for specific people it says that there's no one by that name in my contacts lists. It works on other computers. I've tried both Google Chrome and Internet Explorer and still the same problems.. Please any help would be much appreciated!!
Thank you