U2412M Issue: Display Port: entering power save mode (mac possible FIX)

Have a Mac Pro 4,1 2.66 GHz Quad-Core w/ AMD Radeon HD 6870 2048MB - two Dell U2412M's attached one via DVI the other the DisplayPort. Everything worked great - for a while. Then the displays would not wake after being asleep, instead go into power off mode. Work around was disconnect everything. Power on before reconnecting one display.

Then I found the DVI connected monitor started going into power safe mode. Leaving me working with just the one.

Couple times both displays just blacked out. The GPU fan sounds like a plane losing altitude, fighting to stay airborne, when I have both displays attached. I thought the problem could be related to overheating of the GPU...(another issue)

If these symptoms sound familiar you may want to try going into the U2412M menu --> other settings ---> DDC/CI ---> disable

The "display data channel-command interface'. It allows the display to be adjusted via PC software.

Once I did everything seemed to return to normal. Only been a day... I thought I would share although I could be jumping the gun. 

I know a lot of ppl seem to have this issue. I didn't see any answers. Either way, Mac users have no need  to have it enabled.