If the game crashes while holding (moving) an item in inventory, the item will be lost.

While playing 1.7, I had been sorting around stuff in my inventory, when the video locked up and had to restart the service. When I logged back in again, the item had vanished. I looked thoroughly around the area and my inventory (and chests) to see if I had put it away or dropped it, yet I couldn't find it. I experienced this in survival, but I suppose that it could also happen in creative, if the bug held true. Because of the way I restarted it, it did not create a crash report.

Steps to reproduce:
1: Open up an inventory
2: Click an item so that the pointer is holding it.
3: Crash the game hard.

I should also note that there was another weird issue with a furnace. The flames didn't start to burn down until the last smelt, with a block of coal. It did not seem to happen again.