I have a friend that has a GI that I shopped out for him. I don't remember the 2 switches being reversed. Next time I'm over there I can check it out.
The switch error you mention is from the switch not being activated after so many balls or games. The pin will keep track of number of balls played or number of games played and if a switch hasn't been hit after so many balls/games it will think it is bad and give an error. Activating the switch will clear the error. My friend's GI will get that a lot on some of the ramp switches. You can play a lot of games on GI and never hit all the ramps. So the game will assume the switch isn't working.