anyone have any ideas as to the cause?

 

Well, I dont know about the door lock, but my rear passenger power window just stopped working too, I was about to start removing the panels and take a look, but notice that with the car engine 'On' when I pressed the button to lower the window I could feel the draw in current by the way the engine sounded... so It was not a problem with power... so what did I do? I just slammed the door and it started working again

 

Check the harnesses that go to the window motor and the door lock actuator. If they get power to the harness then you may have to replace those items.