Last time at Disney I got stuck on splash mountain at 4am during extra magic hours. I got on the last log of the day, upon arrival at the station after the first time around we managed to get another go which at the time seemed fantastic. It was all going well until the ride broke down just before the final drop. We were stuck on that final lift hill for around half an hour and it was the day before my return flight to the UK.
I wouldn't mind Kilimanjaro Safari's breaking down, especially closer to some of the big cats, it would give you a lot longer to see some of the animals although it could get quite scary if they got too close, those jeeps aren't the most enclosed!