Some of those music tracks may be in a format or bit rate that is not supported by the GoGear player like AAC or files in variable bit rate may be skipped by the player (For MP3 the jukebox support 32 ?320kbps & for WMA: 5-192kbps with sampling rate 8.0kHz up to 44.1kHz) . Some of the downloaded tracks may be corrupted and unable to playback by your GoGear player. Use the Firmware Utility to restore your GoGear to the factory setting (see ?Firmware upgrade?) . The maximum number of songs that can be stored on your GoGear is 380.