Right... sometimes the iPhone (3G, 8 gig) will not alert me to a message or phone call by tone but will still vibrate. If I turn the phone on and off again, it starts to work but the problem arises once again later. All the settings are correct, restores done etc... Is anyone else having this problem? This is my second iPhone 3G; the first was exchanged due to the same problem. I find it hard to believe I have picked up two phones with the same issue or could it be a software error as my brother has also experienced the same issue but with the message alert only? Any advice/insight/information would be appreciated. Cheers.