How can i fix my central locking, vw golf 1.6 se ?

When i push the fob key once to open the drivers door, then the drivers door dose open but when i push it the second or third time the other three doors do not open, but they do open with the switch on the arm on the inside of the car, this has only happened since the batterie went totally flat, so i assume that there must be some way to reprogramme this fault, many thanks Rick