HTC Incredible :: How To Get Delivered Check Mark Back?

so just to clarify, this isn't another one of those "Why doesn't my message show as delivered?" threads. I already know it CAN be done, I found that out accidentally. It worked once, but I don't know how to make it work again.What I did when it worked: I sent my sister a message and then quickly switched over to iheartradio. Her message wasn't sending and the station was stuck at connecting, so I power cycled the phone. Then the message sent and to the right of it there's a green circle with a check mark. If I touch that, it says "Report" and then the receiver's name and "Status: Received." So,does this only work when there's an error to begin with or what?!