Hi !
I bought 2 weeks ago the GSM shield Rev2
I use it with the UNO board with the example code : "send SMS" , and I had the same behavior : Just the message "SMS Messages Sender"
It was due to the PIN number , I setted a wrong one. So I tried with my mobile phone and then I remembered the correct one and then confirmed it.
Then the arduino goes to the message "not connected"
I had always this message. I was disapointed.
But I found a small button named "power" on the shield. I push it few second
and then the status led switch on and the status led started blinking !!
Then I press the reset button to restart the soft, and it started to work !
I reached to send a SMS to my mobile phone !
On things that still doesn't work, is the serial, I cannot write characters on the serial console.
So I put my number and the text in constant in the code.
And I added a whiel(1); at the end of the loop, to avoid sending lot of same SMS.
Hope it help someone