I'm not sure why but my notification sounds will stop working at a random times. I have to restart my phone to get them working again. I'll have text messages and email without a peep from my phone. Notification volume is at Max and will even play the default tone when adjusted but will not play a notification sound for any event until I restart. I can also now confirm that both my gsII on my account with ICS do this but mine seems to be more frequent. Anyone having this issue?