I was trying to create a iron golem in 1.8 it did not work so I switched over to 1.7.10, thinking I would make it and switch back so I did. a pone the game loading I had lost all of my items in my inventory, I thought maybe it was just the switch but once I reloaded 1.8 I found all my things still gone plus all my items in my chest and even in chest in the generated structure abandoned mine shaft as well.

to cause this bug
1.) play in 1.8
2.) log out and load 1.7
3.) play 1.7
4.) log out and load 1.8
all items will be gone