Disable cross-screen shadows I have a dual-screen setup, which works fine, but there's one annoyance, the window shadows.

If I maximize a window on one screen (or just make its edge touch the edge of one of the monitors), the shadow from that window "crosses" the screen and goes to the other one, creating a useless visual effect which just looks weird, since the monitors are not exactly touching, so the shadow has no usefulness or relevance there.

Is there a way to disable it (but not disable all window shadows)?
In OS X Mavericks there no longer are cross-screen shadows.
You can get this system update from the App store for free.