Central door lock not dropping

[chazza]

My Disco 1 has two new key fobs after years of having 1 dodgy one; however; when I try to lock it with the key fob, the driver's door lock does not drop.

I can push the door button down easily and I can lock the car with the key without any problems. Unlocking with the fob works perfectly.

Any ideas on what to check? In the past I have replaced the springs on each lock to keep the buttons up and took the time to lubricate each lock with grease; so I would be surprised if it is a lubrication problem,

Cheers Charlie