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Recently, for some reason I'm having trouble moving items in my inventory. Instead of just clicking to select, then clicking once again to deselect; I have to click and hold then move it to the appropriate inventory slot and let go of my mouse button. Shift-clicking things won't work either as well as right clicking to drop one item off a stack in the inventory or chest or crafting/furnaces. I'm running in Minecraft 1.8.1 and using a Windows Vista/ Windows 7. This has also slowed down my map making process and stopped my YouTube videos from being put up at all.
If anyone can help me that would be nice.
P.S. I've quit and restarted mc, as well as removed it from the computer and its memory and reinstalled but the problem persists. If anyone can help please do.