I just did a fresh restore to 6.1 on my iPhone 4S. First thing I did was rang my mobile with an Android to test "reply with message" and it sends the message by iMessage rather than SMS. The only way I can get it to send it as an SMS is to disable iMessage altogether. It's bizarre because that number has never been associated with iMessage. When I go to send a text to that number, the iPhone recognises it properly and sends it as an SMS. I can't make sense of what is wrong. It is not jailbroken. Any advise as to what I can do? I notice on twitter a couple people have this issue as well, but there seems to be no solution. I tried to login to Apple Communities, but it is making me choose a new username, upon which it frustratingly informs me that the email address is already taken (no kidding!).