Why can't i Layer from the same program?

How do i layer with a single program? Lets say i have one program which is a drum pgm and i wanna lay down the bass and snare.. so i do. than i wanna lay down the hats and rim shots. but if any of the rim shots or hat lands on the same time as the snare or bass. one wont work.. Its super frustrating. i am constantly making new programs so that i can layer. Anyways . hope i dont sound stupid. i use a mpc 1000 with jjos 2xl

if your program is set to mono then there can be only one hit at a point in time...
make your program poly and try again.

peace jo

TOTALY... wow i feel dumb.. thanks man! i was changing the poly/mono in the voicing section not on the whole program! thanks!