When you put MobGriefing in true, when you click on Q a selected item will get placed in the players foot (like boots). When you put MobGriefing in false, the game will run normally.
VIDEO:
It shows the bug if you don' t understandme(sorry :S)
Environment
Windows 7 64 bits
Intel Pentium Dual Core 2.5Ghz
4Gb RAM (2 Allocated)
GTX 460
Java 7 64 bits
Duplicate of MC-4560, please use the search function to see if your bug has already been submitted. Currently over 50% of tickets are being closed as duplicate.