I'm pretty sure it uses a custom media player, since it uses the file extension .sdb for streams. If you hang around at the snapshot view, does it update? For me it updates each 5 seconds or so. Remember that this is a beta though, so maybe there's a possibility that there will be a update that fixes this?

Anyway if you really want to fix this problem, you should probably report it in the official thread @ my-symbian.com.