This is a bit annoying but...I solved it but I can't remember exactly how! It's just too stressful to replicate the problem now (wimp) -maybe later - however it seems that if the Polarity is reversed by stepping on the Pedal at Power-on - restarting the Np-30 and then some combination of holding down a note(s) while depressing and then releasing (or vice versa?) the pedal will fix it...maybe the more adventurous among you will establish exactly what works...But I think the answer is it ain't broke but is wired in an unusual way? Hmm...