pulseaudio-0.9.8-4.fc9 gnome-session-2.20.2-1.fc9 Don't quite understand why. Other sounds setup in the sound capplet play correctly, and the login sound plays fine in the capplet.
Sound effects are only randomly available, about 1 in 3 gnome-session starts have sound effects enabled for triggers. I'm guessing that Pulseaudio says its esd compat is ready when in fact it isn't. Other sounds seem to be working fine, reassigning to Pulseaudio.
Bug in gnome-session/gnome-settings-daemon interaction. See: http://bugzilla.gnome.org/show_bug.cgi?id=466458