Comment 17 for bug 1093792

do you have two lines at /etc/modprobe.d/alsa-base.conf ?

snd_hda_intel: model=ref
snd_hda_intel: model=auto

!!Modprobe options (Sound related)
!!--------------------------------

snd_hda_intel: model=ref
snd_atiixp_modem: index=-2
snd_intel8x0m: index=-2
snd_via82xx_modem: index=-2
snd_usb_audio: index=-2
snd_usb_caiaq: index=-2
snd_usb_ua101: index=-2
snd_usb_us122l: index=-2
snd_usb_usx2y: index=-2
snd_hda_intel: model=auto