If it's any consolation, I just learned about this feature through your post, and I am having the same thing. No sound. I am running Firefox. It wanted me to download Quicktime player, then failed, and now I have no sound. I'm gonna try IE later and see if it is just me. I'll also see if I can manually download QT.
I have IE, Quicktime, Java (latest update) still no worky.
Didn't work with FireFox for me either.
Good luck, keep us posted on your efforts.
Thanks. I'm running IE. Interesting to see if you get it to work.