I'm having similar problems, specifically with ALSA.
What devices does it use? so far I have done chmod 666 on:
and some others I can't remember - I've just been granting permissions to anything I find mentioned on any ALSA-related site.
Also, I've added my "normal" user to the audio group.
I read at http://www.sonic.net/~rknop/linux/debian_alsa.html
that the /etc/init.d/alsa script might fight with you and reset permissions at startup and shutdown - I'm not versed in scripting language, but my C ain't shabby, and I can understand most of what's being done- it doesn't seem to set permissions anywhere. Both fixes recommended on that page break my modprobe.conf, and convince it I don't have modules installed. I also can't find any evidence of permissions being changed - all of the devices listed above retain their 666 permission throughout ALSA starts/stops. They're also still audio group, and so is the user.
Yet, whenever I log in with my non-root user, I get:
Sound server informational message:
Error while initializing the sound driver:
device: default can't be opened for playback (Permission denied)
The sound server will continue, using the null output device.
And when I log into KDE as root, everything's peachy.
I'm running ALSA 1.0.1, just compiled today, and whatever aRTsd is in debian /unstable.
Soundcard is Crystal Fusion, mosule: cs46xx
I've seen a LOAD of people with this problem, and I've been working on it now for a couple days with no headway. every bit of literature I've read says
chmod a+rw dev/dsp dev/mixer dev/sequencer dev/midi
and I should be rocking - but I'm not!
Can't live without XMMS much longer!