Thank you for your advice cbud. I should have also mentioned that I had my HD1 upgraded by Sony to play MP3s. But sometimes I still wish to transfer using ATRAC as then I can fit more tracks onto the HD1. So I've got SonicStage 3.1 and in "Transfer Mode Settings," I choose "Specified bit rate transfer mode". When 66kpbs(Atrac) is selected, the MP3 file is converted and then transferred. Good. However when 105kbps(Atrac), 132kbps(Atrac) or 256kbps is selected, it just transfers in MP3 mode, in other words doesn't bother converting to those bitrates. Is there anything I can do about this? By the way what is the difference in terms of sound between Atrac3 and Atrac3Plus? Thanks very much.