Vista - Audio drivers for Asus Onboard Soundmax

Hi

I have a Asus K8V Se Deluxe motherboard which has an onboard soundmax AD1980
sound card which is 5.1 capable in xp but since upgrading to Vista Business
it installed VIA ac97 drivers automatically and i only get audio from 2
speakers now the rest are useless. I have check the asus site but there is
no sound drivers for vista, contact asus support and they didn't know when a
driver would be available, its a pity cos everything else is working
perfectly. Do anyone know how i would get 5.1 audio working. If there is no
way can someone please suggest a fully working 5.1 or 7.1 soundcard that 100
per cent works in vista. Any assistancecwould be greatly appreciated

Thanks