There is certainly a problem with the pre-release version; I've contacted them about it. I suspect that they haven't set MIME type definitions on the server, which always creates problems for non-microsoft browsers; and that the use of scripting instead of direct links to audio files is also making things difficult (existing browser plugins not being recognised, and the workaround involving opening the media file in the appropriate standalone program not working).

With luck, they'll sort that out before the official launch on July 1st. It would be a pity if they had only tested their setup in IE on windows-based systems. I gather that there are also problems for Linux users.