Any reason why one 8800 GTX video card would not work in a Crossfire MB like the ASUS A8R32-MVP Deluxe ATX S939 Xpress 3200 Crossfire. I could see SLI not working. But I can't see why one 8800 GTX wouldnt be compatible. However I wouldnt be totally surprised to see no Nvidia card working in this MB as well.
More about8800 crossfire motherboard
give your specs, and make sure you have the latest bios
If it has a PCI Express slot 16x it should work just fine. Just no SLi for you