sound cuts off on mpc

whenever i play a drum sound over a sample it cuts off the sample, is there something wrong here, im new to the whole mpc i use to use fruity loops, anyone ?

Read the manual.

Go into Program Mode (Mode + Pad 7). Hit the pad that your drum is assigned to. Hit Params (F3), and at the top right make sure the "Play" field says POLY. That should fix your problem.

Also make sure the "Voice Overlap" field, middle left of your screen, says POLY.

make sure you didn't accidentally set anything to the same mute group

thanks it fixed the problem but now the sample sounds different then before it was on mono ? it kinda sounds like it has a swing or some kind of interference it doesn't seem right
i have read the book il have to read it again

is this the same as if the sound sounds lower then the rest,
for example today my artner and i was messin with his 1000 i chopped up a bassline into 5 parts and samples 1-4 sound full level and sound 5 sounded lower whats the cause of this all pads play at full level but there was like 2 pads that didnt sound as loud as the rest, it sounds full level with the sounds it came with but out of the 5 chops one didnt sound so load, whast the cause any idea? thanks
oh yeah i dont have the manual so sorry i can't RTFM sorry.