The sound stopped playing, both from console and from X Window.

Sound Preferences, started from System|Preferences|Hardware|Sound from the main
menu. If I click Test, I get a message box with:

audiotestsrc wave=sine freq=512 ! audioconvert ! audioresample ! gconfaudiosink:
Internal GStreamer error: state change failed.  Please file a bug at
http://bugzilla.gnome.org/enter_bug.cgi?product=GStreamer

I also tried to run ConsoleKit in a terminal window and got:

$ ck-list-sessions 
Session1:
	uid = '0'
	realname = 'root'
	seat = 'Seat1'
	session-type = ''
	active = FALSE
	x11-display = ''
	x11-display-device = ''
	display-device = '/dev/tty1'
	remote-host-name = ''
	is-local = TRUE
	on-since = '2008-06-30T10:56:35Z'
	idle-since-hint = '2008-06-30T16:18:45Z'

This is wrong, I'm logged in as kasal, and X window was started by "startx".

My system is a mix of F-9 and rawhide rpms.

If this report can help to fix something, I'd be happy to help with debugging
according to your hints.