Hi Forum, I live with two other people and we all got a 4S. I got mine in November 2011 and the other two are from May and June 2012. Now we all updated to iOS 6 and one of the phones can't go on wifi anymore. It's not the slowness thing, the actual toggle for wifi is greyed out as if it's been restricted. The other two are fine. Any idea how to fix this? A reboot or restore didn't help.