problems with sending sms via arduino GSM shield

I have the arduino uno and arduino GSM shield. I used the sendsms example code under GSM.

I uploaded the code to the uno. My code however stops at "SMS messages sender". So in the serial

monitor I only see "SMS messages sender" and then my code stops running. I think the shield is unable

connect to the mobile carrier? I live in South Africa and am using an MTN sim card. Been struggling with

problem for a while now. If anyone could help me/ shed some light on the problem, that would be deeply

appreciated. :confused:

I tried the pin management example code under GSM. I found that for three different sim cards(different

carrier networks), i got "PIN & PUK locked. Use PIN2/PUK2 in a mobile phone." in the serial monitor.

I live in South Africa...anyone encounter this problem or have solutions?

Put the card in a phone, unlock it and remove the need for pincode.
Ckeck that SIM-boads LED blinks every 3 sec (connected to network)
(blink every .8 sec means "not connected")

It's been discussed before:

http://forum.arduino.cc/index.php?topic=155057.0

might help!

Thanks guys...i checked the link. Have been experiencing similar results. Will implement what was said on the other post and i let you know.