notes cutting out

I know this has been discussed before but I have a drum sample that I"ve choped up into a new program and when I try to play the drum sounds on top of each other they cancel each other out.

I have made sure the samples are mono and that mute groups are set to off and that voice poly is set to poly but it still keeps cutting out. Is there anything I'm missing?

chapter 12 in the manual that probably came with the machine highlights the subject about programs and the differences between oneshot and noteon and a few other things that might be useful to keep in mind.
if you've lost the manual you can download it from akais website for free.
good luck with all that.