Help, I am having major probs with this unit, all was well and has been for a number of months. All of a sudden I cannot hear any output sound when recording, I can see the level meters going on the input, but alas no sound. I've checked and rechecked evrything I can think of, sound works fine on play back, I can record and playback fine, but cannot actually monitor the sound when I am recording, makes it a bit tricky when ya can't hear what your playing.