On mine it was the left rear caliper that kept seizing. Finally, my mechanic disassembled the caliper, gently hammered the brake adjuster cage into what he deemed to be a more appropriate shape with a tiny ball peen hammer (these Italians still know how to work with metal by hand) and re-assembled the whole thing. Has worked perfectly ever since.
My caliper was malfunctioning in that the automatic brake pad clearance adjuster (the metal cage inside the caliper itself and which turns on a threaded rod) was ratcheting up alright but not backing off automatically with each brake application to preserve that factory clearance of 2mm between the rotor face and the brake pad. So, as the pad wore down the 2mm specified clearance was eliminated causing the brake pad to drag. When the rotor heated up due to pad drag the brake seized.