Hello MPC peeps! I know this is an ancient thread, but figured I would put my two cents in... I have been using the MPC5k for a couple months now, and never had a double trigger problem. Needed a portable MPC, so last week I picked up an MPC1000BK, the last new one in the store

Got it home and loaded up some drum programs, and sure enough I was getting double triggers. Very frustrating, especially because I opened up the unit and confirmed that it has the good pads (single rubber sheet). I messed around with the pad sensitivity settings and all, but one in about every 50 or so hits was still a double.. I'm doing 16 and 32nd notes at 175bpm, so double hits are extremely annoying for me!
I have my MPC 1K sitting on a flat table, but noticed that it wobbles very slightly, as if one of the rubber feet is not touching the table. (kind of like an annoying shaky four legged chair at a restaurant, ya know). Well, I put a CD (shim) under the MPC foot, and it is now totally stabilized. Guess what, NO MORE DOUBLE TRIGGERS! I think what was happening, at least in this case, is that when I hit pads the MPC wobbled and caused a double hit as it moved up.
If anyone is having double trigger issues, it may be worth it to make sure your MPC is sitting completely flat on a very sturdy table or mount that has NO give whatsoever. Make sure it doesn't wobble at all by lightly pushing down on the corner edges one at a time. the CD shim seems to have solved my problem completely, now I need to figure out how to make a permanent fix for the road.
Good Luck!!
Scott
p.s. I think this was a non issue on the 5K because it is so much heavier than the 1K, more sturdy too.