Quoted from gunstarhero:Check your drop target. When mine was getting flaky it would drop when the game served up a ball, and that caused an automatic mode start and a launch.
You might just need to adjust or replace the little plastic lip the target rests on when it's up, that's all my issue was.
2nd this^ when I got my STLE the little resting tab was broken on the drop target, replaced it and stopped auto launch, when it sees a trigger it auto fires thinking a ball is in play. broken rest tab = I would hit start, baam off to the races, kept me from picking my modes.
Just order a hand full of tabs b/c they fail over time anyways.
http://www.pinballlife.com/index.php?p=product&id=3511 <- since my GB has 2 drop targets I got a few extra.