After recording a couple of songs using all 8 channels, when I rewind back to the first song and only tracks 1-4 will playback. Tracks 5-8 do not show up on the meters and no sound coming out of the outputs. If I stop the tape at that point, shut the unit down and power it back up, all 8 tracks are restored and work properly. Move on to the next song and that works fine. Rewind to the first song and the problem reoccurs. And on and on. I also tried two different tapes and the same thing happens. The heads have been cleaned with a dry cleaing tape and manually cleaned. If anyone has any insite, it would be appreciated.