Comment # 1 on bug 1040048 from Takashi Iwai

Hm, is it an undead pulseaudio process that may block something?

After logout from the previous GNOME session, try to switch to VT1, and check
whether pulseaudio process is alive.  Kill it if there is, and go back to VT7
and continue to re-login.

I meant it just for checking the cause, not as a fix, of course :)