I set up the SMS example code on a Re:Phone (xadow GSM board + LEDs).
It was working for a couple of week so that I could send an SMS and get some LEDs to light up.
But then it stopped working.
I checked the SIM card by putting it in a phone and I can send and receive SMS messages properly.
But when I put the SIM into the Xadow GSM board and use the serial monitor in the arduino IDE I can see that the board is sending an SMS but it does not receive any messages I send back.
I have made sure the iPhone I am using has iMessage turned off so the messages are sent as proper text messages.
Any ideas on why this might have happened?