no sound from alsa

["Majors, Jason" <jmajors@paypal.com>]

I just set up amd64 etch on my PC. I am running the
2.6.12-1-em64t-p4-smp kernel image on an intel based system. I have the
following kernel modules loaded:
snd_intel8x0           40064  6 
snd_ac97_codec         90308  1 snd_intel8x0
snd_pcm               102792  2 snd_intel8x0,snd_ac97_codec
snd_timer              30472  9 snd_pcm
snd                    63712  24
snd_intel8x0,snd_ac97_codec,snd_pcm,snd_timer
soundcore              15392  1 snd
snd_page_alloc         14984  2 snd_intel8x0,snd_pcm

I ran alsaconf and set the volumes using alsamixer, but I have no sound.
I've tried playing with the different volumes and the different
headphone and line out plugs, but nothing seems to work. The sound does
work when I boot off of Knoppix 4.02.
Has anybody encountered an issue like this? Or does anyone know how to
resolve it?
Thanks.