i have a 51 plate 2.0 ghia 5 door. i can use the key fob and lock and unlock all the doors with no problem but if i use the key it only locks or un locks the door the key is in. if inside the car and i operate the lock switch under the handle, the other doors do not lock or unlock. my sister in law has a y plater and hers is same with the addition of not working on remote either. is there a common fault with these cars and hopefully a common (Cheap) repair