FWIW I think the resetting is to do with a sequence of modes that are started in a certain order, it doesn't pick up a ball that's been locked (or thinks one has but hasn't) and it gets confused. And if one wasn't watching the game intently, a reset could be easily missed... the GI didn't cut out or anything, just the display resets and the flippers die.
To Stern's credit though, the boot sequence is VERY quick
Glad to hear it's fixed though. Just couldn't understand how it happened quite frequently to us but didn't get noticed all that much at Expo (though I do remember them mentioning it during the PAPA stream, I should re-watch it).