I have a 2011 Sorento EX - 19000 miles - Still under warranty. 3yrs/36K bumper to bumper. I had a flat - Took the tire to dealer. They told me that the nut in the tire sensor was cracked resulting in loss of air. They said that it wasnt covered under warranty!. I argued that it wasnt "wear and tear" -without success. Anybody have similar problem?