first time had my 08 Acadia out on the road driving 65 miles per hour for more than an hour. About hour 3 I get a System Moniter Alarm (and what looked like an exclamation in brackets)...I check and it says my left tire has 35psi, my right is just -----. Everything was fine after I made husband pull over and check tire. This alarm came in and out throughout the whole trip. I called my dealer who had just serviced my car. Checked everything and changed oil. Had the tires off. They claim they couldn't have possibly done anything to it (okay). Haven't had it in to check because not getting the alarm in town. Anybody else experience this?