I had the touchscreen replaced on my radio/navigation unit. After reinstalling the GPS showed my location several miles from my actual location. I recalibrated the unit so that the cursor (car icon) showed my actual location. I used my cell phone GPS (longitude and latitude) to be sure that both agreed. My problem is that it won't stay calibrated. I have to recalibrate every 2 or 3 days. Has anyone had this problem or know how to solve it?