PCR-30: I'm using a "hold" pedal (CC 64) whose polarity is the reverse of twhat the PCR30 expects, and I cannnot find a way to change the polarity in software. My Roland RS5 allows me to do this easily, so I expected the PCR to as well. How can I tell the PCR30 to reverse the way it responds to this so that "on" and "off"would be effectively reversed?