On preupgrade from Fedora 15/16, no audio devices. Pulseaudio service doesn't start. This keeps going into F16, so we will add more.
To see if you have this problem:
(Not found, no permissions errors)
If it's OK, your audio devices will be displayed, and something else is wrong.
There is a unique problem from F15, where pam symlinks aren't updated. This is the best fix, from root:
authconfig --updateall --nostart
rm -rf ~/.pulse
If that doesn't work, I did this with username=root on FC16. It survived boot,and worked for all users. Don't do this unless you need to.
su -c "usermod -aG pulse,pulse-access,jackuser,audio root"
The other solution was chmod o+rw /dev/snd/*, you shouldn't have to do this one.
If you start in runlevel 3 (terminal) it won't take effect until you go to graphics (init 5). (pactl list won't work until gnome is up.)
Flash Plugin Problems:
If the sound icon dissappears after the first playback from browser, you may have this problem.
When you add a graphics card with HDMI, there are two sound output sources, the motherboard, and the sound card. The default is to output to both at the same time. This fails for me in FC16 with HDMI and AC97.
From the sound icon (gnome 3) edit the settings, and change the output sources to the HDMI audio. (TBD, save this setting)