Cindori,
I guess i'm a first then. Check the image below.
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I read what you said was supported and not but wasn't going to let that stop me. Only problem is on boot, you have to move to nvidia, and then move the cable back to ati, but ati works for me as you can see on VGA, and stable.
VGA working? That's great news! Hopefully it will stay stable. Do you plan on trying it in slot 0 again?
I'm currently using an HDFury converter to go from my 4870 ZHFC's DVI w/HDCP to VGA, but can't get 1920x1200 working (1920x1080 is the highest I can get it to go). I need VGA because my HDMI connector on my Westinghouse 24" MVA panel drops out on occasion, but I can use DVI/HDMI for boot purposes if needs be.
I may have to upgrade my 4870 to one of these if this works out for you in the long run. I really would like for it to boot in Slot 0 (either off of DVI or VGA) without any problems though.