Fox 3,
I'm runnin 2X 4870's as well. When I checked the Multi-GPY box in 1.019, I suffered huge FR loss, I mean low in the single digits. . . SLIDE SHOW. Along with that, I suffered trees and balloons popping in and out.
I have since UNchecked the multi-GPU box, since it ran fine before, and will continue testing tonight.
Best of luck to you
Ted