Yep, happened to my back right side about 12 months ago; I took the dorr trim off, and unplugged as many connectors as I could (2, IIRC), put it all back together and it magically worked. Same thing happened a month ago to the rear left hand side, but I never got to fix it; it fixed itself inside a week. Luckily both times, the windows were stuck up (on a previous car, I have had the window stick down, in the rain!!).
Try taking the door trim off and fiddle with the connectors - I used a circuit tester to confirm it was getting power to the circuit when using the switch, so I thought that the motor had blown, but then it worked once i put it all back together.