This is not a kernel/sound bug, it seems to be another issue altogether, possibly (assignable to) gdm or gnome-session, as evidenced by the fact that you can hear something when the gdm greeter appears.
Again, please _attach_ (last time you commented inline) the output from ``amixer -c0 && lsof /dev/dsp* /dev/snd/*'' while logged into GNOME.
This is not a kernel/sound bug, it seems to be another issue altogether, possibly (assignable to) gdm or gnome-session, as evidenced by the fact that you can hear something when the gdm greeter appears.
Again, please _attach_ (last time you commented inline) the output from ``amixer -c0 && lsof /dev/dsp* /dev/snd/*'' while logged into GNOME.