Leon .. are you suggesting there should be a "system" pulseaudio server (running as root / system wide kind of thing?)
I'll ask the question another way (to any developers)... what is the start-up process for pulseaudio ? when should it start (I saw the /etc/init.d/ and /etc/rc?.d/ for pulseaudio) .... perhaps there should be one and there is NOT..
Upon a fresh boot... I've switched to console and 'ps auxww | grep pulse' and there is no server when sitting at the gdm login screen ... so the gdm sound generated there must be ALSA ...
And my attempt to figure out how the pulseaudio server starts (under the normal user account) when an X session starts (via gdm) ... I gave up on finding it hoping somebody here would tell me where.
To me, this problem feels like a conflict between developers on the exact start-up process and something gets hung (perhaps a racing condition, or something not started in correct order).
All I know is there are several solutions that I know of... and none of them are perfect unless I hear something from a developer that clarifies the start-up process and can provide a set of instructions to verify things are configure correctly and/or starting up correctly.