Don't believe this. I've got electrical gremlins on my drivers front window. Sometimes it works normal and other times doesn't work at all. Opening and closing the door sometimes starts working again. Locking the car and unlocking then open and closing the door sometimes gets it going. 

Anybody got a clue what's going on

I would check the wiring isn't broken in the loom that runs from the A pillar to the drivers door as they can break where the wiring is articulating when opened and closed all the time....which can then lead to fractures. Should just be able to peel back the rubber gaiter and see if there is anything amiss.

Let us know how you get on with it

Cheers   Trevor