pcm kmix, alsa problem with sis7012
 

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]