Trouble with drums

I have a sample which im having trouble drumming over, its got some kind of off timing, but when I play my drums over the sample it all sounds fine during recording, but when it plays back it isn't what I played.

Why isnt the mpc recording what i am hearing and playing?

You probably have the 'quantize' turned on (Timing field) - turn it to OFF and it should record exactly how you want it.