e46 coupe electric mirror - doesnt find/stay memory position

[spants]

My e46 330ci clubsport coupe drivers side mirror is misbehaving. When I use my key (or the wifes key) to remote unlock it, the mirror does not move to the correct position. If I change the position, store it and reopen the car, it will move again rather than staying put.

What could be the fault? The passenger one is fine...

regards
Tony