I did just happen to go in and check right before I read this. It was turned off. Then when I turned it on it was set up to receive iMessages at my email addy instead of phone #. And I've had issues using email to receive iMessages in the past. Now that your phone # works on the mac I went ahead and just deleted the email addy. However, when I start a new text the send button is still showing up green for a person who has an iPhone. I'm wondering if theirs shut itself of too?