It became very annoying that whenever I entered video chat after an OS X restart, the microphone wouldn’t be selected. I would have to go to the settings and reset the microphone as input, then restart the browser, then re-do the video connection.
Turns out this has been a known problem with Snow Leopard for several releases. I finally found one Internet site with a working solution (sourced from an Apple forum): http://www.basvandijk.eu/2010/09/12/mac-pro-sound-defaults-to-internal-speakers-after-restart-or-shutdown/
Re-iterating the solution, three commands in terminal are all that’s needed to fix the glitch: delete the audio preference folder, then create a new one and set its permissions.
$ sudo rm -r /Library/Preferences/Audio
$ sudo mkdir /Library/Preferences/Audio
$ sudo chown -R _coreaudiod:admin /Library/Preferences/Audio
Go back to the sound preference panel and set the audio to the one you prefer. This will recreate the settings files. Reboot the system and observe that it now works.
What’s up with Apple anyway, for letting such annoyances persist? OTH, for those of us who find no compelling reason to advance to the Lion series of OS X releases, thanks Apple, for still supporting Snow Leopard in mid-2013.