Over Dubbing issue

Hi, I have just bought an mpc 1000 and everytime i go to make a beat i take a sample and record the sequence, then over dub and add the drums...however when i add the drum beats in over dub mode the original sample become silents....can anyone tell em what I'm doing wrong?
Dyson

First, are you using one program for your samples and a separate one for your drums? If you have one program for everything then setting the program to mono will cause your drums to cut off your samples.

If it's not that then it may be a polyphony issue. The way around that is to resample a track.

thank you mate, sorted, very helpful!

I'm having the same problem, It seems It just won't play a drum track and the sample at the same time, one always cuts the other off. All pads are set to poly, and I know its not the samples I've been trying because I even tried resampling them but to no avail! Please help me!