This may or may not be related to your problem. I have a Roland sustain pedal and it won't work right either with my Pa1x. No matter what I do the polarity is reversed - sustain is on all the time until I depress the pedal. I have several other pedals, Yamaha, Kurzweil, Alesis and all of them work fine, just not the Roland.
Maybe it's an ancient Japanese shogun thing...
Bob