So my wife and I both have an iPhone 4S from AT&T (both unlocked). She is going to Japan later this week and usually she takes her prepaid Softbank phone with her but I offered to cut her sim to use in her iPhone. When I put the Softbank sim in her iPhone I get a message saying there is no sim. I put it in my Phone and it works fine. I went back and forth used both my sim tray and hers. I also have a cut down T-Mobile sim and it works in both of our phones. I can figure out why the Softbank one won't work in her phone only. Any ideas that I can try? I might be sending her off with my 64 GB 4S and be stuck with her 16 GB 4S for 5 months.