Since it doesn't handle being unloaded gracefully. To do so, add something like: const char * g_module_check_init (GModule *module) { g_module_make_resident (module); return NULL; } 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.
Fixed.