I just upgraded my friend's iPhone 4 to iOS 5.0.1. I put the phone in restore mode and did a fresh upgrade that way. I enabled iMessage for him. He doesn't have a 3G connection, but there shouldn't be anything wrong with using Edge. Now, I can send him iMessages from my iPad. I enter either his Apple ID or phone number, and I can send the message. He can also receive it. However, on my iPhone 4 (also iOS 5.0.1) I have previous SMS message with him on his phone number. On my iPhone, I can't get it to send iMessages to him. It still defaults to SMS and won't recognize both the phone number and Apple ID as being registered with iMessage. I tried creating a new thread, but that didn't help. What can I do to force my iPhone to send iMessages to my friend's iPhone?