Help!!!!!

When i chopped up the drums and record it my mpc plays the drums, but when i want to record another part or sample of it it seems like some parts of the drums are missing.

Can someone please help me with this.

what?

did you chop the drums in chopshop and made sliced samples with a new program?
If thats the case, when you make a new program for sliced samples, the samples are automaticly put to "mono". Change em back to "poly". check if you have a group mutes also.