Our MDX has about 70,000 miles on it, and the battery has been replaced once about 3 years ago. Randomly, the nav will start cycling through various commands on it's own, seat Memory will no longer works. And worse, the transmission will start shifting abruptly and harshly--or not shifiing at all. Once you turn the car off and restart, everything will be fine for a while. Has anyone else had this problem? What could it be? Is it battery related?