I had a problem with the X32 running Linux 2.6.13 where the audio device was there, but I couldn’t always hear the output. I found this post mentioning that the headphone sensor and line jack sensor both need to be muted, which worked for me. Here’s the card info from the model I have:
miker@spark:~$ cat /proc/asound/cards
0 [I82801DBICH4 ]: ICH4 - Intel 82801DB-ICH4
Intel 82801DB-ICH4 with AD1981B at 0xc0000c00, irq 11
I’m using the alsa driver snd_intel8x0 and made the change using the alsamixer curses tool (although apparently you can turn on the sensor switches for the volume panel control under Gnome as well).