MPC tempo changes?

This thing is really starting to hurt my creative process. For some reason, while my mpc is playing the beat I'm working on, it will speed up the tempo in the middle of the playback until it loops, then it will play at normal speed again. It used to happen every now and then, but now it does more and more. It really throws off the vibe.

Does anyone have any idea what I could do about this??

okay, so nobody has ever had to fix their mpc before or what?

What you describe has never happened to me so I have no comment.