Had problems with mine since the first cold day after buying the car. Now I get to guess whether the changer will :
1) Just ignore discs because their diameter is 0.000037562mm too small for the mechanism to pick up and the HU will therefore display NO CD1 when trying to change to the disc.
2) Recognise that there is a disc in the slot but decide that it doesn't fancy listening to New Order today and display CD ERROR when trying to change to the disc.
3) Decide that heavy traffic isn't enough to deal with and display ERROR when trying to change discs, meaning that I have to reach over, open the glove box, eject the caddy and put it back in again, cursing that the 10-disc changer in the boot of my S40 never gave me a minute's trouble.
Never bothered going to the dealer with any of this because I knew that it would behave itself perfectly when they checked it out and they'd blame the discs not being clean.