Unfortunately, because of how proprietary Sony is, it's a difficult task to get it working, let alone being able to use SonicStage in Linux. The linux kernel would most likely have seen your player (type dmesg in a terminal) but it doesn't know what to do with it. So, unfortunately, I had to buy a flash-based mp3 player (Sansa m240). There are some tools, but they don't allow ripping music to the player.