Mouse scrollwheel, binding double commands

It is not possible to bind mouse wheel up and down on different things. I try to bind mouse wheel up but it also does what I have bound on mouse wheel down. The graphic in settings shows that I bind mouse up or down, but in the game it becomes a double command. This was not in the open beta as far as I can remember, nor in any other BF I have played. Tried different things, but nothing will work properly without some double command. I also (sometimes anyway) get a warning about double command that scroll up is bound to switch weapons, even though I do not have anything like that bound, there is not even that option (thats is called "switch weapons") in the infantry menu as far as I can find, only in vehicle wich i have unbind.