I was having this problem for a while. At the time I had never installed or changed anything on the G. I took it in to Sprint and everything checked out fine. The tech told me he "reset the phone on the network" Whatever! He probably just let the thing sit there until I picked it up. Well, It was fine for about a week. Then it started again! I finally took it back to Sprint. A different tech said the same exact thing. He said the same reset crap. Well the phone still had the problem for a month and then it went away. I really doubt this issue has anything to do with any setting or any software on the phone. Changing the notification settings wouldn't cause the phone to rings hours later after the call came in when I turn the phone on. Thanks!