[CentOS] Reset audio controller w/o rebooting?

[Bart Schaefer]

As I mentioned on a thread about flash-plugin a few days ago, I'm
having trouble with my sound device getting "stuck" and thereby
causing problems for anything that accesses it, like video playback.

Rebooting the machine "fixes" it for a while, but it's unpredictable
for how long -- sometimes months go by without it recurring, sometimes
it happens every couple of days.  Right now I'm in one of the latter
phases.

Any suggestions on how I could reset the controller without having to
reboot?  (Or suggestions for where else I might ask this question?)
Below is output from "lshw" for the audio controller, and "lsmod" for
the sound modules that are loaded.  This is CentOS 4.7.

        *-multimedia UNCLAIMED
             description: Multimedia audio controller
             product: CK804 AC'97 Audio Controller
             vendor: nVidia Corporation
             physical id: d
             bus info: pci at 0000:00:0d.0
             version: a2
             width: 32 bits
             clock: 66MHz
             capabilities: pm bus_master cap_list
             configuration: latency=0 maxlatency=5 mingnt=2
             resources: ioport:d400(size=256) ioport:d000(size=256)
memory:ff6fd000-ff6fdfff


snd_intel8x0           36237  3
snd_ac97_codec         65425  1 snd_intel8x0
snd_pcm_oss            52857  0
snd_mixer_oss          22081  2 snd_pcm_oss
snd_pcm                92613  3 snd_intel8x0,snd_pcm_oss
snd_timer              28357  1 snd_pcm
snd_page_alloc         14541  2 snd_intel8x0,snd_pcm
gameport                8641  1 snd_intel8x0
snd_mpu401_uart        11457  1 snd_intel8x0
snd_rawmidi            28133  1 snd_mpu401_uart
snd_seq_device         12105  1 snd_rawmidi
snd                    58149  12
snd_intel8x0,snd_ac97_codec,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_timer,snd_mpu401_uart,snd_rawmidi,snd_seq_device
soundcore              13345  2 snd