2500/fantom playback problem

i have them midi together and i made a drum pattern, then when i go to play the fantom onto the mpc for the melody...the melody plays back choppy...I have poly on and i have TC off ...what else could it be for the playback melody to be so choppy

are your pads in your program set to different mute groups? if they are, then some pads might be cutting the playback of other pads off..