Initially this started while doing some light gaming on TF2 with my 2013 Macbook air and Steelseries Rival mouse. I realized that whenever I press shift I am unable to scroll with my mouse (because I use shift as crouch, and scroll wheel for weapon switching). For the sake of efficiency I would like to be able to simultaneously scroll while pressing shift, (if possible) however, pressing shift disables the scrolling function with the mouse. What's strange is that if I press shift I am still able to scroll with the track pad using two fingers. Does anyone know how I might go about addressing this issue if possible? I have tried this with other keys and it appears control and shift are the only keys that disable the scrolling function on the mouse. I also think it's tied to a larger issue (as well as the external mouse) with trying to bind the keys to the other functions. For example, I can't bind capslock to crouch in game because capslock is responsible for capslock and other functions but I can bind crouch to ABC.... or any other letter. It's pretty troublesome because I like to game when I am not studying or working and the inability to bind certain keys makes it very difficult to do so, Any help or information would be appreciated.