This happened to me on an iPad Mini running iOS 6, and my sister was on an iPad 3 running iOS 6. I've read posts about something similar to this happening on Android though, too.
We were on a local multiplayer world.
After having FINALLY convinced my sister to play Survival with me on Pocket Edition, she started up a world on her game and I logged on. Please keep in mind that this is her world, not mine. The sun was rising, and I started to do a little Lion King reference, but she couldn't see the sun, even with far render distance. We realized the issue was that she was running Alpha 0.7.2, but I had updated to Alpha 0.7.3. Because we like discovering interesting stuff, I crafted 2 chests and placed them together to make a double chest (that wasn't added until Alpha 0.7.3). Seeing as my sister hadn't updated, it just looked like there was one normal sized chest to her, and it only held the space of a singular chest. We then closed the world and she updated to Alpha 0.7.3.
When we hopped back on, our double chest was gone and was replaced with a singular chest. We figured this was because it was, again, her world, and she had started it on Alpha 0.7.2 and a double chest to me looked singular to her. It was a loss of 8 planks, but oh well.
After upgrading to double chests, I started throwing stuff in them, but I noticed that to me, the GUI only read "Chest" and had the capacity of a singular chest, but to my sister it read "Large Chest" and had double that. I started breaking the chests and placing them back down in double-chest format to try to get it to fix the issue, but after doing this a couple times, my game crashed.
To prevent this from happening again, I decided to just have my sister give me stuff I needed out of chests, and to put in stuff I wanted to put in the chests. We plan to continue this method until the issue is hopefully fixed in Alpha 0.7.4 or 0.8.0. Also, (only on this world) to me, double chests looked like two singular chests right next to each other, sort of like how you can place a Chest and a Trapped Chest right next to each other in the Computer version without them connecting to make a double chest.
