The Bug:

When the anti-aliasing settings are over 1 the crosshair doesn't invert colors as it does usually. This van be a problem for monitors because the Crosshair Always being white can burn it into the screen which can be annoying 

Heres an example:

In the Image above the crosshair should be black but it's white.

How to Recreate:

Set the anti-aliasing to a number over 1.