When I look at it with GPU-Z it only is showing the card in my primary PCI-E slot, even if i'm actually running power and my monitors through the secondary card. I'm not sure what numbers you were referring to for the manufacture or frequencies, but it all looks normal to me. Do you think this could be an issue with my mobo?
EDIT: I just stumbled upon this... http://www.asrock.com/mb/vga.asp?Model=870%20Extreme3&c=CF
Although it does not specifically say it supports the 5770 under windows 7, it does say that it supports the 5870 and the 4850 with crossfire. Would it be safe to assume that the 57xx series are included?