[CentOS] Pidgin and (lack of) sound on CentOS 4.6

Sat Jan 5 04:15:49 UTC 2008
Bart Schaefer <barton.schaefer at gmail.com>

When I start pidgin from the Applications -> Internet -> Internet
Messenger menu, my sound device stops working.

I think this has something to do with the Gnome applet.  I appear to
end up with two (sometimes more) copies of the "gaim" process running
-- such that if I use the right-button menu on the Gnome applet to
quit pidgin, a login dialog is stil left behind and sometimes won't
exit.  I'm guessing these multiple gaim processes somehow deadlock the
sound device, such that even after I kill them, no other process can
play audio.  Pidgin/gaim itself can't play sounds in this condition,
either.

I've tried using "lsof" to find all processes that have the sound
device open and force them to exit or restart, but that doesn't help.
Once the sound goes out, only a reboot brings it back.  The flash and
mplayer plugins for firefox/seamonkey are still able to play (silent)
video in this condition, but starting up e.g. gmplayer blocks forever
trying to open the sound device.

Googling turned up this:
http://blog.turbulentsky.com/2007/12/pidgin-has-no-sound-in-ubuntu-gutsy.html
but I have no reason to be confident that would apply to CentOS.
Searching on gaim instead of pidgin finds stuff that's four years old
and almost certainly not relevant.

Unfortunately I don't have much experience with audio apps on linux
(or anywhere else, for that matter).  I've never had any luck creating
a .asoundrc or trying to get all my applications to agree on whether
to use ALSA instead of OSS (although I take it OSS is pretty much
obsolete now, I don't even know if the kernel in RHEL4 is recent
enough to use ALSA by default).  So if anyone has any clues to share
on how to go about diagnosing this, I'd appreciate the help.

Here are the sound-related modules from "lsmod":

snd_intel8x0           36237  2
snd_ac97_codec         65425  1 snd_intel8x0
snd_pcm_oss            52729  0
snd_mixer_oss          21953  2 snd_pcm_oss
snd_pcm                92485  2 snd_intel8x0,snd_pcm_oss
snd_timer              28229  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            28005  1 snd_mpu401_uart
snd_seq_device         12105  1 snd_rawmidi
snd                    57765  11
snd_intel8x0,snd_ac97_codec,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_timer,snd_mpu401_uart,snd_rawmidi,snd_seq_device
soundcore              13089  2 snd

Tell me what shovel to use, and I'll dig up any other system
information that may be needed.  Thanks in advance.