We have hundreds of Mitel 5340 IP Phones, we did a software upgrade 3 weeks ago since then a small group (around 15) of these phone's, Mitel screen saver displays on the phone, when I go into the phone's setting and disable the image, it will only keep the correct screen setting (page 1) for a few hours but then it goes back to Mitel's screen saver. Does anyone know how to disabe Mitel screen saver permanently, so it will stop coming back?