The Naxos music service uses a Windows Media Server to stream music from their servers to you computer. This works pretty good if you work on an PC but can cause problems if you're a Macintosh user.
Microsoft stopped developing the Windows Media Player for the Mac several years ago. A third party company is now developing a plugin that allows windows media files to play on a Mac. Unfortunately it doesn't support everything that is needed on the Naxos site. You can play individual tracks but you can not use playlists.
You need to do two things to get Naxos working:
To uninstall Flip4Mac navigate to your Applications folder and find the Flip4Mac folder. Inside you'll see an installer script. Launch the installer and it will actually uninstall the plugin.
Download the Windows Media Player Installer Launch the installer and it will install the windows media player.
After installing everything close your browser and then reopen it. This time when you go to the Naxos site every thing should be OK.
The windows media player is several years old while the Flip4Mac plugin is still under development. It's possible that some video sites will work better under Flip4Mac than they will under the older media player. This is a trade off. If you want to use the Naxos site this is the best arrangement.
We'll keep you posted if things change.