So about four months ago I put on some drilled/slotted rotors on my em1. Not the junk eBay ones, these cost me a pretty penny on pro civic. Yesterday, all the sudden it sounded like I needed new pads, which I replaced at the same time. So I pulled in the garage, took the wheel off on the rear driver's side, and about an inch of my rotor had been sheared off all the way around. All the others were still in great shape. I didn't think to take any pictures, but I'll definitely put some up first thing in the morning. What could cause that? The pads had no abnormal wear, everything else was in good shape except the tons of metal flakes all over my rim.