well, I found that the switch was completely broken off the circuit board. I solved the problem by soldering some wire from one end to the other and closing the circuit. Windows work fine at all the passenger doors now. I can't block them out, but not a problem for me.
Just did the same to mine. Mine was broken on one side, so was making contact occasionally - thus the intermittent problems. Jumpered the two connections just to the front of the switch and all is working fine. Guess you could wire in a replacement switch if lockout is needed.
Was a bit apprehensive getting the control knobs off to get to the circuit board, but just gave them a good pry and they popped off.
Thanks for sharing the fix FullSack. Gave me the initiative and solution I needed. Wife has been bugging me to get it fixed for several months now!
Gary