To get most of the information out of the way, here's what I've found out as of now. Twitter, Facebook, text messages, Gmail, do not vibrate and they are all set to vibrate. Phone itself in the settings>sound is set to vibrate always. If I manually turn down the phone to vibrate, vibrate works for notifications but when sound is on, it does not. Unrooted Motorola Droid 1. I have tried everything to figure this one out but I am officially stumped. I've had this phone since Dec 2009 and this is the first time it has ever done this. It vibrates when I receive calls but it will not for any notification in general. I have also tried using various apps that are suppose to make the phone vibrate on notifications but none have sufficed. Help would be appreciated if anyone has any suggestions or ideas, I just can't wait to get a new phone now if this is a problem that I can't fix. Thank you for any future responses.