One important case to analyze is the MIDlet update scenario. A first consideration is that it is not possible to update a trusted MIDlet with an untrusted one. It is, however, possible to update an untrusted MIDlet with a trusted one and it is also possible to update a trusted MIDlet with another trusted MIDlet.
In case of updating a trusted MIDlet with another trusted MIDlet, and assuming that the protection domain is preserved across the update, the permissions and the permissions mode ought to be preserved. Therefore, if the user has manually given a session mode for a particular function group, this setting will be preserved across updates.