Rescanned as directed. Took a couple of days but then got all my channels back plus a couple. Two days later my 4 PBS channels vanished and I can't get them back. Have rescanned many time. Unhooked my antenna (which has brought in PBS for 2 years) scanned as directed then hooked up again and rescanned. No luck. I've called FCC and they are no help. Called my TV manufacturer and they did a scan from their end with no luck. They say nothing else they can do. UNC-TV doesn't answer - just a...