Originally Posted by NoMoreSymbian
Wish I had the answer. Mine started doing this also in the past couple weeks. I never know the fone can't be reached until a family member emails me and I see it in the computer. I reboot the fone and voila, texts flood in.
My fone is not rooted and haven't added any apps except the snowfall Xmas live wallpaper.
I purchased my Sprint S3 on black Friday and have had the same problem as others here. A restart gets it working again, but it's really irritating to my wife and others trying to call or text me. Email still works though. I don't know it's not working until she asks me why I don't answer her calls or texts. This is happening frequently enough (several times a week) since I bought it. I love everything else about the phone. Sounds like the radio is stopping much like the Original Epic and if I remember correctly the Moment too until they supplied an maintenance release to fix it. There's absolutely no indication anything is amiss.
My phone updated to JB almost immediately after activation, so I don't know if that's the problem.