I was talking to a tech last night trying to get my three monitor set  up to work and he told me to disconnect the crossfire.  Does anyone have a three monitor system working in crossfire?  On my top 6850 I and connected into a DVI and the display portal on the bottom 6850 I and connected into the DVI.
For what ever reason the monitor that is on the display port is much brighter screen.  All three monitors are the same model