Last night I drove to a friends house to watch Wrestlemania which was right around 20 miles one way. Parked my truck, hoped out and began walking toward the house. The smell of something burning caught my attention and I turned to look at my truck. Smoke was coming from the right rear wheel/rotor. Not sure what caused this and I'M POSITIVE I wasn't drving with the emergency brake on. Any ideas as to what my problem may be before I take it to the dealer? Truck is an '08 CCSB 4x4 offroad w/3:73 rear gears and factory 20" wheels and tires.