Had this happen pretty bad to mine today. Put it in reverse and had to press the accelerator to get it to break loose. Loud crack when it finally loosened, then a loud thump everytime the wheel went around. Did a few shift into neutral stops and it helped, but didn't completely fix it. I've had it happen before, but this was by far the worst. Has anyone had their pads replaced by the dealer? Did it stop the problem? Was it under warranty?