Mouse curser dissepears when clicking in smaller windows

So I am multiboxing D3 and I am running dual monitors, instance 1 is fullscreen on monitor 1 and monitor 2 has instances 2, 3, and 4 tiled with a square of desktop visible. I have the program setup so when I click in one of the other instances it does not switch to monitor 1, since the instances are hotkeyed and sometimes i like to control things from within the smaller instances without sending that instance to monitor 1.

Problem is when I click or hold down the mouse in one of these smaller instances on monitor 2 the curser dissepears, and re-appears when i release the mousebutton (both right and left click)?

Thoughts?