Hello to everybody, I was an exchange student in Canada for half a year an had a koodo prepaid SIM card. It worked perfectly fine on my Iphone4 (bought in Germany). Unfortunately my phone got broken and I got a new Iphone4 (bought in an APPLE STORE in Vancouver). My koodo SIM-card worked in that phone too, but I'm back in Germany now and my phones tells me "No Service" or "Invalid SIM" all the time when I put my old german SIM-card in. The german SIM-card is the same like before my koodo-card. Some people say theres a SIM- or net-lock on it but I'm not sure. I hope anybody knows what to do. Thanks in advance.