I have a Droid X and just upgraded to Gingerbread. Usually, SMS notifications work just fine. However, if I leave a conversation with a person open and turn off the screen (or if it goes to sleep) then I won't get any sort of notification when a new SMS arrives from that person. If I get an SMS from a different person then I'll get notified, but not the person with whom I left a conversation open with. If I close the app and return to the home screen (or even navigate away from the current conversation) before turning off my screen, then I do get a notification when they reply. This is frustrating because usually, when I leave a conversation open with someone, I am expecting a reply from them. I have missed many texts because of this. Before upgrading to Gingerbread I got notifications all the time. Any idea what's going on or how to fix this?