FC5 audio problem

[Loren Lockwood]

I recently upgraded from FC4 to FC5 and found that Audacity no longer works.

Audio CD's play okay, the various grunts and bonks of system sounds are
heard, mplayer plays mp3's, so does zinf (after claiming that the sound
system is busy) and so does mpg321.

But Audacity gives me the message, "There was an error initializing the
i/o layer.  You will not be able to play or record audio.  Error: Host
error."

A day or two ago System | Administration | Soundcard Detection could not
produce sound.  When I clicked the appropriate button, the text
immediately below changed from "-- Stopped --" to "-- Playing --" and
almost instantaneously back to "-- Stopped --", without my ever hearing
any sound.  Now, but some magic, it works correctly.  It changes to "--
Playing --" and stays that way as long as the sound is playing.  I can't
think of anything I have done which would fix that.

If only the same thing would happen with Audacity!

I have uninstalled and reinstalled Audacity a couple of times using yum
with no solution to the problem.

Anybody have an idea what has gone wrong?

TIA

Loren