I use Debian 3.0 [Woody], the bf24 flavour.
I installed alsa-base, alsa-utils and alsaconf using dselect.
Then I installed alsa-modules-2.4.16-k7 (Because I have an Athlon XP). This required the installation
of kernel-image-2.4.16-k7, which uses initrd.

(I think I installed all these OK, because 'uname -r' gives me 2.4.16-k7 (It gave me '2.4.18-bf24' before)

Then I used alsaconf to configure my VIA8233A chipset. (It created the file /etc/alsa/modutils/0.5,
which I moved to 0.9, because my driver is 0.9beta12, but alsaconf is 0.4.3-b4) Then I unmuted most
of the channels with alsamixer and set the volume to ~half.

lsmod gives me:
Module                  Size  Used by    Tainted: P  
af_packet              11912   1  (autoclean)
tap0                    2528   1  (autoclean)
snd-seq-oss            23264   0  (unused)
snd-seq-midi-event      2920   0  [snd-seq-oss]
snd-seq                37196   2  [snd-seq-oss snd-seq-midi-event]
snd-seq-device          3968   0  [snd-seq-oss snd-seq]
snd-pcm-oss            35744   1 
snd-mixer-oss           9184   0  [snd-pcm-oss]
snd-card-via8233        4896   3 
snd-pcm                48576   1  [snd-pcm-oss snd-card-via8233]
snd-timer              10432   0  [snd-seq snd-pcm]
snd-ac97-codec         23232   0  [snd-card-via8233]
snd                    25352   2  [snd-seq-oss snd-seq-midi-event snd-seq snd-seq-device snd-pcm-oss snd-
mixer-oss snd-card-via8233 snd-pcm snd-timer snd-ac97-codec]
soundcore               3684   5  [snd]
vfat                    9500   1  (autoclean)
fat                    29720   0  (autoclean) [vfat]
nls_cp437               4384   5  (autoclean)
ntfs                   47712   3  (autoclean)
apm                     8908   0 
keybdev                 1696   0  (unused)
usbkbd                  2944   0  (unused)
input                   3424   0  [keybdev usbkbd]
usb-uhci               21412   0  (unused)
usbcore                49536   0  [usbkbd usb-uhci]
rtc                     5560   0  (autoclean)
ide-disk                6816   6  (autoclean)
ide-probe-mod           8096   0  (autoclean)
ide-mod               131436   6  (autoclean) [ide-disk ide-probe-mod]
ext3                   55872   1  (autoclean)
jbd                    35016   1  (autoclean) [ext3]
unix                   14020 119  (autoclean)

echo-ing something (e.g. a .au file) to /dev/dsp doesn't seem to work, as I hear nothing and the
console is locked (until I press CTRL+C and get:
bash: /dev/dsp: Interrupted system call
The XMMS doesn't work either. It just locks when I press PLAY.

Can anyone tell me what am I supposed to do in such case?

NOTE: Something else: doing
/etc/init.d/alsa stop
/etc/init.d/alsa restart
(or even force-stop or force-restart) gives me:
Storing ALSA mixer settings...done.
Shutting down ALSA sound driver (version 0.9.0beta10): no. (sound is being used by pid 503 )
(pid 503 - or another number, doesn't matter - is aplay-0.9)