I've been making an adventure map in the sky, 50 blocks over void, on flat map "only air". The map is about quick running (speed 20) without jumping (jump boost 200 - "corrupted"). When I fall of, I'm in void (y:0) about 3 secs. But when I try to jump about a small while before I fall, I'm about y: -30 in one second. It is not important, but... It's a bug.