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)
MC-8608
MobGriefing Item Bug (With Video)
Resolved
Duplicate
0
Marcos J
(Unassigned)
Unconfirmed
armor, gamerule, mobgriefing, slot
Minecraft 1.4.7
Retrieved
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.