Newbie quick question for item auto pickup.

[s3kShUn 61]

I know this has to be an easy fix but I cant seem to find it. Whenever I try to drop an item it just spins around me then appears back in my inventory. It's just kind of a nuisance. All I would like to do is turn it off. I am playing Hexxit but I dont believe this is a specific problem with that modpack which is why I am posting in the general Tekkit forum. Thanks in advance!