GEMS has a bug where you can unset-then-set out from under it. That needs fixing. But the moment they unset and changed the election title, all the memory card images changed, even if GEMS didn't notice at the time.
Then they actually did a "full" unset to change the number of candidates. When they set-fored again, GEMS checked to see if the memory card images were the same as they were when they were programmed. They weren't. The election title was different. So it invalidated them all. Had they actually hit "apply" when they unset to change the election title, the same thing would have happened. They didn't have to change the number of candidates. The memory cards were already toast.
This was all explained to GBS the last time they tried this stunt.