If you copy a mp3 file to you’re HTC HD2 windows mobile device you can get the error: “The device has either stopped responding or has been disconnected”. This error occurred only when I connected my HTC HD2 with Active Sync. If you connect you’re HTC HD2 to you’re PC and choose “Disk Dive” in the Connect to PC screen on the HTC HD2, coping files won’t display the error and copying is much faster.