Why is sample muting when tapping out drums

Im new to this but i've been picking things up so here's where i'm at.
I've recorded my sample into my mpc got it on a two bar loop , on track one
But now when i go to tap out my drums on track 2 the sample cuts out
What is the deal?

You probably have the program that you are using in both tracks in mono mode.
set it to poly.

Hey thanx alot that was the problem. Thats been holding me up for a while.
Now I can get to work