I've had to replace several of mine like Paul above. My experience is that the lock (the white/clear latch piece) broke due to the door being dropped when closing. I mentioned this to my dealer (or maybe it was at the factory) and their answer is 'don't drop the door'. Since then, I haven't broken any more and I don't drop the door when closing it. Let the door down easily and either push it closed to latch or use the latch handle.
Paul is right, the replacement is about a 10-15 minute job with a pop rivet tool and screwdriver for the latch cover removal/replacement.
Robb & Sue Steinheider
Lexington the Dalmation
03 Ultimate Advantage/09 Honda Fit Sport Toad