So this is what has happened ... My NW-HD5H had lots of music on it, some was ripped from CDs through SonicStage 3.3 and 3.4. Others was mp3s that was transfered using sonicstage too. All the music files were stored on my NW-HD5H (my computers harddrive is tiny!). All files were working fine. I then upgraded to Sonicstage CP 4.0. After I had connected my NW-HD5H to the computer and SonicStage went through the whole artist link info and so on I disconnencted my player and a lot of my files will now not play when the player is disconnected from the computer. When I try to play them an error message appears on the lcd saying "track error, cannot play file" or something like that. When I just skip thorugh the files without playing them, all the files that cannot be played is missing information in the bottom left corner syaing what type of file it is (mp3, atrac, atrac3plus and so on). So ... I connected my player to the computer again, now remember, all my files are stored on the player, not the computer. When I now try to play the files through SS CP4 everything works fine. They come up with the correct file type (Mp3 and so on). It seems that this is only affecting files that was ripped from CDs but I'm not completely sure about this. Has anyone else had this problem?