strange thing happens to my phone. I was able to unlock my t-mobile S3 with OP's instructions. However, I took out the SIM card and used on the iphone 4s for a few weeks. Now when I put back the SIM card into the GS3 phone, it asks for security code to be able to use the phone. The problem is I've never set the screen lock with security code in the beginning. How do I bypass this? Thanks!