Since it doesn't handle being unloaded gracefully. To do so, add something like:
const char *
g_module_check_init (GModule *module)
to the end of canberra-gtk-module.c.
I've tested this and it does prevent the module from being unloaded, and thus prevents your desktop from dying when you play with the gtk-modules gconf settings in gconf-editor.
Fixed upstream. Need to upload a new version soon.