XFX nForce 680i LT 2nd PCI GPU help needed

I got another GPU to fold on, and had to swap my 2 8800GT's to a spare computer. This computer has the XGX nForce 680i LT mobo. It runs both cards fine, but will only let me overclock the main card. RivaTuner sees the other card, but all overclock options are greyed out. Any ideas on how I can overclock the 2nd GPU?

The cards are not in SLI, WinXP system. I know the card will overclock, if I swap them, whichever card is in the main PCIE slot will overclock, the one in the 2nd slot will not.