Since the latest update I have noticed that if my Galaxy Nexus (android 4.0.2) is on standby for a while that the notification icon goes AWOL (Absent WithOut Leave).
I have to go into the settings and switch the notification icon off and then back on to restore it.
This didn’t happen with the last regular build (I didn’t install the beta build).
I have recently had an android update from 4.0.1, but that pre-dates the update to AMS 1.0.1473, so I don’t believe that is a suspect.