Sound rack switches mpc sounds

sorry if confusing but i got an mpc 4000 and a triton rack hooked up to it controlled via midi keyboard. problem im having is once i record something with the sounds from the rack it saves the sequence on the mpc but when i switch sounds on the triton rack it is switching the sounds on mpc as well. guess my question is how/can i add multiple layers of triton sounds to mpc without messing up previous layers i just recorded?

I too have a triton rack. But since I haven't used it in a good minute, I'll just do a lil guessing and say make sure you're using it in "multi" mode.