I've installed slackware 9.1 on my pc at work some time ago. But i got this problem... the "pcm" slider of KMix didn't work properly. It would slide into MAX or MIN position only. when i try to move it to a more moderate position it slides back to MAX... and makes the sound hard to bear Moreover, the "volume" slider doesn't have any effect on the sound level.
The problem appears also in alsamixer where the <PCM> is not active at all.

(I have installed slackware 9.1 to my home pc too, which has an old ISA yamaha sound card. but there i managed to get everything work just fine)

So here is some info about my work pc

from lspci:

00:02.7 Multimedia audio controller: Silicon Integrated Systems [SiS] SiS7012 PCI Audio Accelerator (rev a0)

from lsmod:

Module Size Used by Not tainted
snd-mixer-oss 11992 1 (autoclean)
snd-intel8x0 17156 1
snd-pcm 55904 0 [snd-intel8x0]
snd-timer 13252 0 [snd-pcm]
snd-ac97-codec 37240 0 [snd-intel8x0]
snd-page-alloc 6004 0 [snd-intel8x0 snd-pcm]
snd-mpu401-uart 3136 0 [snd-intel8x0]
snd-rawmidi 12512 0 [snd-mpu401-uart]
snd-seq-device 3920 0 [snd-rawmidi]
snd 27460 0 [snd-mixer-oss snd-intel8x0 snd-pcm snd-timer snd-ac97-codec snd-mpu401-uart snd-rawmidi snd-seq-device]
soundcore 3332 1 [snd]