Ok so I got XFX on the phone.
They had me try a few things..
1) Boot windows 7 into safe mode and see if the black screen happens.
Answer: It does not. Windows 7 defaults to 800x600 and it had no issues with the monitor going into power save.
2) Use the system with only the 1 monitor plugged in connected via display port. I did this and I still had the monitor going into power save randomly.
3) Change resolutions from the default 2560x1600 to a lower resolution. When I changed it to 800x600 I no longer had the blackouts. As soon as I bumped it up to 1680x1050 the blackouts started occurring. At 1280x800 I did not get any blackouts.
At this point, the XFX guy did not think it was a driver issue. He thought it was either going to be the monitor or the card. Once I get the replacement monitor in I should be able to narrow it down further.
He also wanted me to change the display settings on the monitor to 1:1 so there was no scaling.. It made no difference.
Does a UAC (may need to renable these to check) prompt force your DisplayPort monitor to shut off? I had the same issue, and it was corrected when I installed clean 9.10 catalyst drivers (cleaned out nvidia drivers).
http://www.hardforum.com/showthread.php?t=1461773