how about recompiling your kernel with this driver
http://www30.brinkster.com/cem/linux/ac97_codec.txt
"First do
$ mv ac97_codec.txt ac97_codec.c
Then overwrite the old driver situated in /usr/src/linux-X.X.XX/drivers/sound/ by the new one and recompile the kernel with sound enabled and VIA82CXXX sound and midi enabled"
comes right from his website....