So in a recent snapshot, Mojang said they had fixed the problem with the exit menu not saving the map. It still isn't fixed, even in the most recent snapshot, and when I press esc then go back to the game, it stops rendering, there aren't any noises unless I punch/mine blocks, and blocks don't drop when I break them. Is this just me or are other people having this problem?
EDIT: I found some strange things in the map... I've loaded it several times, and I just keep finding weird things. I got some pictures: