pan-daemon expects the signal com.nokia.icd /com/nokia/icd com.nokia.icd.status_changed string:"DUMMY" string:"DUMMY" string:"DISCONNECTING" string:""
I have tried sending the signal by hand but it 's ignored because it doesn't come from the expected service.
icd2 doesn't send that signal when instructed to disconnect with a dbus method call, that's why the problem happens, but I have observed that the signal with string:"IDLE" (instead of "DISCONNECTING") is always sent.
So, I think the best fix is to change pan-daemon so it calls the script when receives the "IDLE" signal.