Last week I took my one-year old 2008 S40 to my dealer for a warranty repair. The nav and audio systems were totally inoperative. The dealer replaced an electronics control module and the CD changer. When I got the car back, I checked out the operation of the two systems and found that the radio presets and all the addresses programmed into the nav system memory had gone missing. Reentering the radio presets only took a few minutes, but I was not looking forward to reentering the 100+ destinations in the nav system. Fortunately I had all of them in written form as taken from my V50's nav system. The drive home, with a couple of stops, took about two hours, at the end of which the nav memory was still empty. Two days later, I got into the car to start reentering the nav system addresses and found that they had all magically reappeared. Anybody have any idea what happened?