Phantom notifications of Galaxy Note driving me nuts
Mine was the Yahoo app. It was driving me mad. Nothing in the status bar, just a two-tone ding-ding. All the notification boxes in the app were unticked but it was still dinging.

Go to the app, - Options - Account settings - Notification Settings - Choose sound. If you touch the "Yahoo! Default" I bet you hear the two-tone ding. Select "No sound". I haven't heard it since it did that. If that doesn't fix it, the app is coming off the phone. Yahoo need to get real. That is not OK.