..Sorry it took like a whole day to reply, but I was scratching my head about this until I finally remembered we made F12 into a "Change Viewpoint " control you can configure some 2.1 patches ago. X_X
So then, are you by any chance saying you set "Change Viewpoint" to Joy6 specifically? Also, are there any other controls set to Joy6 perhaps? (since apparently we use it as a default for Jump)