I had been using G400s' buttons that by default change the DPI for toggling zoom in or out and zeroing when control's pressed.
After my G400s broke, I got a G402. The equivalent buttons don't work like they should. Both keys just toggle the zoom in and sometimes even shoot at the same time.
When trying to bind the keys from Arma's control settings, instead of their actual functions ("Play/Pause" or "Next track" in this case) they show up as blanks - "".