I am having the same issue ever since the hotfix update was installed. I am currently stuck at 125 blocks high floating around. If you find a water source in the side of a mountain, it will kill you once you hit the ground or launch you into the sky. When I respawned, I am still floating next to my bed or I spawn 100+ blocks in the sky... I really don't want to lose this world - been working on it for quite some time.
Update: I tried creating a new world and it still starts out with my character floating just above the dirt. This is ridiculous...