Hello Cat people!

I have 2 identical MacPros running same version of Cat. They both have the same graphics cards. Nvidia Quadro 4000.
One is set-up as Main Cat, the other as Spare

I have the Macs running thru a Lightware 8X8 DVI matrix. The outputs are set up as Output 1 is HUD, Output 2 is output to LED wall.

The machines are set up the same with the same exact profile in the Display prefs. "Generic RGB Profile"

For some reason when I route the outputs to the LED wall one of the machines is not nearly as "video black" as the other. I only see this on the screen 2/output 2

Has anyone seen this issue before?

Thanks
Ken