Have you tried using a different browser from your normal choice? Perhaps something in your browser settings are interfering, and a change to another one would work for you?
For instance, it works for me on Internet Explorer and AOL browser, but so far, I haven't been able to get it going on Firefox (although others have). This is counter-intuitive to me, to have IE and AOL work when FF does not, but I'm sure its the fault of my FF settings.
Also sometimes, (like right now), it just doesn't work at all.