Hi guys, I noticed a strange sound like air leaks when I used sustain (m audio s2) on px 350, but the problem never occurred on my ex px 150. On px 350 it has more reverb sound than px 150, how do I turn it down? One more question, I used to play digital keyboard, the way I played was I kept my foot on the sustain at hard as possbile. But the problem I got on casio px150 px350 was the sound (string, violin ...) would never stop until I let my foot go. Please tell me how to fix this problem. Thks guys.