Could it be someone before you has replaced either the switches or the window regulator and wired them incorrectly. For the fuse to blow there must be an electrical short somehwere. Time to strip the passenger door liner and/or the switches me thinks
You replied before I saw your post!
If it was wired incorrectly then surely it would blow straight away? (This is why I am baffled!)
The passenger side switch works normally, its the driver's side which is the wrong way round, so maybe they re-wired or put a new switch in there.
So why does the window work with a new fuse for a day, even when turing the engine on and off and just using the car on and off normally, yet once its been left for some time over night it stops working? Maybe when it starts up it sends too much current to the window or something?