My Yamaha KX88 seems to be stuck in Dual Mode. The result is it sending duplicate midi notes to my sequencer, which creates phasing or dropped notes. I've tried the reset to no avail. As soon as I select either Single Mode (MS1) or split mode the keyboard freezes and I have to power it off/on again. I have also tried rebooting with the MIDI cable going from the out to in creating a midi loop. I heard that's a trick that sometimes works. Does anyone know these keyboards?