Inventory Goes Missing When I Log In

I had many many things in my inventory, went to my house and logged out. I logged back in some hours later and found that not only my entire inventory was missing, but so was everything in my chests. I have experienced this twice, both since I have begun playing in 14w03b. I do make a backup of my world, so I haven't lost anything permanently, but it is an inconvenience to have to reload the world if my stuff goes missing.
I don't really know how to recreate it, as I said I just logged out and logged back in. Both times, I was playing under the snapshot. I hope this has been helpful.