I have a XFI card on my Asrock Dual-SATA2, and it works fine. My old Audigy didn't work though, possibly because it had a firewire port on the card too... problem is that the PCI slots on this motherboard share IRQs with the USB controller, which can cause problems. In my case, after installing my Audigy, my mouse was disabled due to insufficient resources.
Unfortunately there doesn't seem to be anything you can do about this as the IRQ settings appear to be hardcoded. Disabling devices makes no difference; onboard audio uses IRQ 18, USB ports use 20 through to 23. Disable the onboard audio and IRQ 18 is freed, but nothing will use it... when you install your card it will dump it on IRQ 20-23 regardless of what you do.