Hello everyone I have a problem with my Iphone 3gs. I bought this phone from someone who upgraded to the 4s and all I want is for it to work on my sim card which is not At&ts. The front screen is stuck on trying to activate but it will not read my sim card. i recently found out the software was upgraded to IOS 5.01. Is there anyway I can downgrade my software and if so how can I do that? When I try to read my phone through Itunes it doesnt tell me any info on the firmware. Please someone help and thanks in advance!