I received the 1.7 update today and first thing I noticed after loading my Minecraft world is that I spawned underwater, even though I saved underground the day before. Turns out that after this update my location seems to get shifted around quite significantly whenever I load up my world. Also the lighting around the world border chunks seems to be pretty much broken. Actions that cause a light update seem to fix it, but only for as long as the world is loaded. Quitting and reloading the world breaks the lighting again. I'd also like to use this opportunity to point out that the redstone ticking area is still incorrectly defined for Old world types (see MCPE-34015). In any case, I hope this bug can be fixed soon as I'm quite fond of the old word type and I'd like to continue my adventure in it. But in this state it is starting to become quite unplayable.

I don't know if youtube links are allowed, but I also made a video showing the issue (it also shows the incorrectly defined redstone ticking area, MCPE-34015, which is still unresolved):
https://youtu.be/krXFMn0gDK8