Description of problem:
Intermittently, sound on my F9 desktop will die. Trying to play audio
afterwards gives the following errors:

macbeth:~% paplay /usr/share/sounds/generic.wav
Failed to drain stream: Timeout
macbeth:~% aplay /usr/share/sounds/generic.wav
Playing WAVE '/usr/share/sounds/generic.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo

No sound comes out in either case. Or as root:

macbeth:~# paplay /usr/share/sounds/generic.wav 
X11 connection rejected because of wrong authentication.
E: client-conf-x11.c: XOpenDisplay() failed
Connection failure: Connection refused
macbeth:~# aplay /usr/share/sounds/generic.wav
X11 connection rejected because of wrong authentication.
E: client-conf-x11.c: XOpenDisplay() failed
*** PULSEAUDIO: Unable to connect: Connection refused
*** Is your sound server running?
*** See: http://www.pulseaudio.org/wiki/Troubleshooting
aplay: main:564: audio open error: Connection refused

What, I can't play audio without connecting to an X server now?
How is that even vaguely sensible?

Anyway, pulseaudio is still running:

macbeth:~# ps -f -p $(pgrep pulseaudio)
UID        PID  PPID  C STIME TTY          TIME CMD
fer       8031     1  0 Oct25 ?        00:08:03 pulseaudio -D


Version-Release number of selected component (if applicable):
pulseaudio-0.9.10-1.fc9.x86_64

How reproducible:
Intermittent

Steps to Reproduce:
1. Start an X session
2. Do some stuff. Sound is working fine.
3. Wait a bit. Do some more stuff. Sounds stops working


Additional info:
When trying to play audio, the following appears in /var/log/messages:
Oct 27 22:29:14 macbeth pulseaudio[8031]: module-alsa-sink.c: Error opening PCM device front:0: Device or resource busy