It may not help, but try moving the soundcard to another pci slot.
When I recently re-installed windows XP pro on my nforce3 mobo, my audigy2 never initialized and windows would not see it. Resetting the mobo bios to force it to shuffle IRQs didn't help. I moved the soundcard to another slot and it was recognized, but there were address range conflicts and some of the soundcard features were not recognized. I moved the card back to it's original pci slot and it all worked again.
So...
Maybe the connector had corroded a bit and it just had to be reseated, but...
I think it's a compatibility issue and it just needed to get kicked in the head before it would work. The card wouldn't initialize until the drivers were installed, and the drivers wouldn't install until the card was recognized. Forcing the mobo to assign a different irq by moving it to another slot was what did the trick.
At least that's what I think happened. So bottom line, try putting the card into another pci slot.