I´m posting this for informational purposes:
I own a mk2 station wagon with "Comfort pack". The other day i noticed that the drivers door wouldn´t keep the car locked, with or without the key in proximity, the darned thing would always unlock!
First i tested the electronics - thought that perhaps the keyless entry would be shorting... but no...
Then i got a second opinion, took the car to a specialized electrician who confirmed my suspicions.
So i took the door apart - and took out the lock. So it turns ou to be a small spring on the latch which wasn´t doing it´s job properly. In the enclosed picture i have pointed ou the spring in red. All i had to do was to "open" the spring arms a little, (be careful with the load) and put it back together!! Working like a charm now!