as far as i know, there is no switch in the passenger's door, there is just the handle.
Usually attached to that there is an actuator that will pull the wires that connect the handle to the lock down. that could be stuck or jammed.. it sounds in your case its the actually drivers side switch thing which are known to get dodgy connections. Take that out and try wiggling the wires and see whether it comes back to life or acts intermittantly.