In the newest versions of Pocket Edition I've had a lot of trouble with items in chests disappearing, the chest itself disappearing from the world, or inventory in chests not updating after saving/quitting the game. In one instance I was able to pull out some granite blocks from a chest, save, quit, reload and pull the same granite blocks out again.

This is kindof ruining the fun of the game

I didn't have this problem with the 0.9.x series of Minecraft and logged in 50-100 hours no problem. Only since the game updated after September of last year and version 0.10.x game out did I start having problems with disappearing items/chests.

No screenshot available. I put it in a chest and it disappeared...