NW-MS70D Problem

Has anyone had any problems playing ATRAC3 or ATRAC3plus files on their NW-MS70D? All my mp3s are on my hard disk. They convert to ATRAC3 and ATRAC3plus with no problems and transfer to the device. Most of them play, but some don't - the player says they are playing but there is no sound. Sometimes it's a whole album, sometimes just a few songs from the group. The sampling rate of the MP3s doesn't seem to affect it, or if they are converted to ATRAC3 or ATRAC3plus at 48 or 64kbps. It's always the same tracks that won't play! Would be thankful of any help/suggestions.