ALSA problems with 2.6.18-rc3

[Andrew Benton <b3nt@ukonline.co.uk>]

Hello World,
I use the optical digital output from my computer and normally it works
well. However, with a 2.6.18-rc* kernel I have to use alsamixer to get
any output from it. I tweak the levels till it's working and use alsactl
store to save it. Normally, when I reboot it's enough to have a
bootscript run alsactl restore and it should work,  but as I said, with
a 2.6.18-rc* kernel it doesn't. Every time I have to use alsamixer to
change the <IEC958 P> setting to A/D Conv and then back to AC-Link again
to get the diode to come on and start sending a signal to the amplifier.
And the problems don't stop there. At first it sounds fine but after a 
few minutes it starts to develop a harsh, tinny, metallic, distorted 
quality and it becomes unlistenable.

According to alsamixer v1.0.11, the card is an Intel ICH5 and the chip
is an Analog Devices AD1981B

Andy