MEGUIARS DA PWR PAD FNSH PD

I used one pad a few months back to wax one of my vehicles. When I grabbed it and put it on the DA to do another car last week, the backing material that sticks it to the DA separated from the pad, so I had to use the second pad that came in the pack to wax the car. When I was finished with the car, I checked the backing, and sure enough, it was separating from the pad. Neither the Compound pads nor the Polishing pads are separating, I was able to use the same pads for both vehicles and they are still fully functional to do another car or two. Just the wax pads are separating. Maybe Mequiars can let me know if I got a bad set or if this is a common problem.