Do you have a TPMS? (Tire Pressure Monitoring System) As you may already know, heat expands and cold contracts. The same thing goes for your tires. As your tires heat up, they may read a little on the high side, and vice versa. If I fill the tires in my Sentra (which is equipped with a TPMS) to 32 psi like the manufacturer specifies, I can drive around for maybe 45 minutes to an hour before the TPMS light goes on saying that I've got low tire pressure or a flat. I regularly set my tire pressures high in order to compensate for the loss in pressure when the tire heats up. Just my .02. I hope the stealership takes care of your issue before any real problems occur.

Cheers

Dave