You have to go into params of the prgm that you plan to change and set each pad to MONO. then set each one to a mute group. (like mute group 1).
Think of it this way since this is basically the definition:
MONO = 1 Voice, or only 1 voice can sound at a time, so if you play the same sound on the same pad very quickly - say at like 16 tripplets every time u press the pad again you arent gonna get overlapping of the same sample, its just gonna cut it off and replay it from the start.
POLY = More then 1 voice that can be sounded at the same time. What this means is if you have a sample on a pad and then u repeatedly do the same thing, its going to keep playing the whole sample ALL the way through over and over till all cycles are done and the voices are all gonna overlap.
Hope that helps.