Gameplay bug

I don't know why, but every once in a while for a day or two ill have no in game mouse (visual only). I can still right click and left click and target things, but I cannot see where on the screen my mouse is at any time except for by the arrows from my move commands, or the highlighting of a minion, etc. I have had it before, but it just went away, I don't know why but it comes and goes. What am I doing?