Comment 8 for bug 1236249

The ubuntu-system-settings and indicator-bluetooth branches I've linked here attempt to handle things more gracefully whenever indicator-bluetooth can't work with /dev/rfkill -- it attempts to fall back to just calling org.bluez.Adapter::SetProperties("Powered", on/off)

This is an improvement; unfortunately, it doesn't seem to be a complete fix yet as powering on/off on the desktop is unreliable in the latest nightlies, even when using bluez' command-line utilities to power off & on again. I've filed that separate issue as bug #1238672