You die when spawning in a new world.

I created a new standard survival world, no cheats, no seed and upon spawning I was stuck in the floor bobbing up and down. I tried making more worlds and found that you can get out of the hole by jumping and moving forwards but if you stay in the hole too long you die in a wall. Also spawning with a bonus chest causes the chest to break and the contents of the chest will be on the floor.
To reproduce the problem just make a new world on standard in survival mode and watch the magic happen.