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.htm... 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.