Tcs kicking in on dry pavement

I have a 2009 Touring CX-9 with approx. 6000 miles. The TCS system has been engaging on dry pavement at inopportune times. On an onramp, going 60 mph down the highway etc. The TCS indicator light flashes (car with squiggly light) and the car will down shift from 6th gear down to 4th. Sometimes the TCS off light will then come on as well and stay on for a short time, but then both lights go out. The car will run fine for 10 miles, 20 miles or sometimes only 3 miles and then it may kick in for a short time and go out. I took it to a dealer last week and they said there were two error msgs associated with the yaw control. They cleaned the sensors, but could not duplicate the problem. I live in midwest with alot of snow lately, but this problem is not happening on snow covered streets. Any ideas or suggestions? Obviously I am going to take the car in next week, but any similar problems may be helpful for mechanic. Thanks

For 2008 model, there is a TSB on TCS light on - cause is YAW sensor.
Here is the number/summary
http://www.ford-trucks.com/tsb/tsb.php/m-MAZDA/d-CX-9/y-2008/t-5662

Insist on replacing the yaw sensor to your dealer. It is not safe to drive with TCS kicking in randomly. If the dealer disagrees, call Mazda corporate directly.

One another note, think about getting rid of the OE tires. They will be bad on snow and ice.

Problem fixed

I took my CX-9 back in and they did find a faulty yaw sensor. Because the TCS off light was intermittent the first time I took the car in, fault codes were displayed, but the yaw sensor tested o.k. This time, the TCS light stayed on and when they again tested the yaw sensor, it failed. I now have a new yaw sensor installed and have had no problems. Thank you to ceric for the reply.