[rlw]

The S60 locking system appears to be from the same supplier as that used on VW Passats '98-01. We had the same problem with the Passat. Sometimes leaning into the front passanger door from the outside fixed the problem. The car went into the dealer several times for adjustment and they finally got it right. No parts were replaced. Maybe you'll get lucky and just need an adjustment of the mechanism inside the door.