i need help with my mpc500

whuts up, so after i record a sample and lay it on a track, i start a new track and try and lay my drums down, but the sample will cut in and out. the sample is fine until i try and add stuff ontop of it, i wanna know what it is im doing wrong to cause this

thanks

1) Make sure your samples are polyphonic for your program and not monophonic
2) Make sure you aren't using more than 32 notes of polyphony (16 if all your samples are in stereo)
2a) if you are using stereo drums, might be worth converting them to mono as most drums can be placed in a stereo space where you want them instead of how they were recorded.
3) Probably not, but you might be referring to clipping and not dropped notes