On my sister's phone (and I've checked the contact, and reentered the number) when she receives a message from a certain number, the other number on her account and replies to it, the message seems to be sent to the 7 digit number, without area code, and so it fails. She keeps having to resend messages, as a new message, to the number typed in in full. On receiving a reply, simply responding to it results in another failure. This is samsung moment to samsung moment, only happens with the one contact, and doesn't happen on mine. Anyone have any ideas on what's screwed up?