Intermittent problem with driver and passenger side windows: Use driver's side controls to roll up driver's and/OR passenger side windows - but when they reach the top of the frame, they immediately roll back down. Won't close tightly; I can leave a 1/8" gap at the top, then quick turn the motor off and they'll stay up. Sneaking feeling is there's an underlying extensive/EXPENSIVE wiring problem. Anyone have any tips or tricks?