The pedal gets used all the time. This is the pedal I've been using daily with my Roland RS-70 since the day I got that synth. The Roland has no problem reversing the polarity with this pedal.

It's just not working in the NP-30. I find it odd that I got it to work once, but since the batteries died and after putting in new batteries I cannot get the pedal to work again.

I'll be calling Yamaha to make sure though. This pedal should work. It's a simple on/off pedal. The keyboard is supposed to reverse the polarity so that pedal can be used. It's the keyboard that's not functioning as it should. Again, after 50+ tries (of tuning the thing on and off.., which is what really killed the batteries fast)., I finally got it to work, but the batteries died, and I'm back at square one again.