I have the exact same issue,
my garage has played with the microswitch whilst fixing another fault with my windows. They informed me that it is the actual lock that needs replacing- a simple job i believe. Anyway I will race you to Ebay to buy a driver door lock.
To confirm, with mine, the window will not drop on the driver side, the lights dont tell you they are on and also you will notice that the flasher for the alarm is not blinking on that side only.
But the alarm is still active and the car locks using the fob and the physical key so it is not a biggy at present.
Try the microswitch though - there are feeds here about that too and how to do a bodge job though for £40 a lock of ebay would be my preffered option, a new lock via my garage is I think about £100- £150.