Sound device weirdness with Xorg, ALSA and udev

[Simius]

There is a most intriguing phenomenon I've been encountering ever since I installed Xorg.
When xdm starts, and I log in, X programs complain about not being able to open the sound devices. (gnome mixer applet says it can't open /dev/mixer, xmms tells me to check the soundcard, etc.)
However, then I switched to a virtual terminal, logged in as user (NOT root), and ran mpg321, it worked perfectly. And what's even more weird is when I switched back to X, everything under X was working perfectly too - Gnome mixer applet, xmms, everything... I logged out and back, and still, sound was OK.
But every time xdm is restarted (not only at reboots, but after /etc/init.d/xdm stop / start too) the sound breaks again. I have to go to a console, and run mpg321 after xdm is started, and then everything is fine.
I can't really pinpoint the source of this weirdness. It is simply too weird and unlikely to be posted as a bug, I don't even know WHAT package might be the main culprit. ALSA? udev? XOrg? Gnome? ...
All ideas and similar experiences welcome...

[Darian]

Are the permissions/ownership of any of the sound devices different after you switch to the virtual terminal? If so, you could add a chmod command to /etc/conf.d/local.start or /etc/X11/xdm/GiveConsole.