on the cars ive worked on, if it loses it memory it wont drop.
try reseting them, press and hold down on the window switch, when it reaches the bottom, hold it for 5 seconds, release, and then press down again, then go up, and when it reaches the top, hold for 5 seconds, release and then press up again.
well thats the procedure on other cars ive worked on. should be pretty much the same.