constant sound

I have my mpc 2000xl connected to a roland fanthom keyboard but when i play notes on the treble clef side of the keyboard (high pitch notes) the note sticks and plays constant like i'm pressing down on the key on the keyboard.......when its not connected midi the keyboard works ok...so i know the problem is not with the keyboard

not familiar with the fantom keyboard, but maybe the way the keys are mapped on it. maybe you have a certain octave set to sustain or something? just a suggestion. not sure if its correct, but good luck