Hi all,
I've noticed that when I have the 3gs on my desk at work, I can hear it vibrate intermittently and when I check for a call there is nothing new or for SMS etc. My wife mentioned this on her 2g too. I believe this happens to me when my ringer is on and to the wife when hers is set to vibrate. But for both phones there is no incoming activity when it vibrates. I do however have the app "notifier" installed. They are both jailbroken and on 3.1.3. Maybe the app is causing this? Haven't tried uninstalling but just wanted to know if anyone else has this issue. Thanks!