ALSA device not found by some users... why?

Some users on my Fedora Core 8 system cannot seem to access any ALSA devices, while some can:

[tim@servy ~]$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: AudioPCI [Ensoniq AudioPCI], device 0: ES1371/1 [ES1371 DAC2/ADC]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: AudioPCI [Ensoniq AudioPCI], device 1: ES1371/2 [ES1371 DAC1]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: AudioPCI_1 [Ensoniq AudioPCI], device 0: ES1371/1 [ES1371 DAC2/ADC]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: AudioPCI_1 [Ensoniq AudioPCI], device 1: ES1371/2 [ES1371 DAC1]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 2: I6300ESB [Intel 6300ESB], device 0: Intel ICH [Intel 6300ESB]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 2: I6300ESB [Intel 6300ESB], device 4: Intel ICH - IEC958 [Intel 6300ESB - IEC958]
Subdevices: 1/1
Subdevice #0: subdevice #0

while:

[tim@servy ~]$ su mpd2
Password:
[mpd2@servy tim]$ aplay -l
**** List of PLAYBACK Hardware Devices ****
<empty list>

User mpd2 needs access to ALSA devices bc I'm running MPD (music player daemon) as this user. When this daemon tries to access ALSA device hw:0,0, it gets an "Error opening ALSA device: hw:0,0 No such device" error. (But if I run the daemon as 'tim' or root there are no such errors.)

I created a new "audio" group, made all sound devices (/dev/snd/, /dev/dsp*, /dev/audio*) accessible to the "audio" group members, and added the mpd2 user to this group, but I still get the same errors. In fact, the only way I've been able to get past the permission problem is to put the new users into the root group, which is not an acceptable solution to me.

So this seems very much like a case of bad ALSA device permissions, but I don't know what else I can do to fix it. Do you? What am I missing?

The /proc/asound filesystem seems to be fully populated and accessible by both tim and mpd2. My ALSA Driver Version is 1.0.15 (Tue Nov 20 19:16:42 2007 UTC).

Since I'm using FC8, I was beginning to think that PulseAudio was behind this. I've followed the threads on FC8 audio problems, but none of the suggested solutions have worked for me. (I have ConsoleKit and avahi daemons running and have removed alsa-plugins-pulseaudio and am still getting the same errors.)

I would appreciate any suggestions or clues anyone might have.
Thanks,
Tim


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