Easily dupable in xen. Cryptic dialog regarding OAFIID:GNOME_MixerApplet.
Obviously it shouldn't crash if there is no sound card. Either silently fail or
run or whatever. But not crash. Poor user experience.
(this bug also exists in FC6)
We fixed this I think. It was gst-register taking so long to run that the
applet was timing out.
Reopen if you still see it.