Hi Everyone! I don't know if anyone has encountered this problem with Iphone 4 but I am experiencing sever Iphone crashes after updating to IOS 5.1.1. Symptoms: - Unlock screen won't respond, - Apps freeze after launching (especially maps, navigation), - Can't answer calls, - Can't hung up calls, Sometimes these symptoms last from couple of minutes to three or four hours! So I can't really rely on the phone. I've tried the following: - Hard reset (many many times) - didn't help - Restore (restore from back up) - didn't help - Restore (set up new Iphone) - didn't help (sometimes the phone was unresponsive during initial setup before I could restore anything from backup) - I completely turned off overnight, and in the morning when I turned it on the phone started to work again, but after thirty minutes or so symptoms were coming back again. The phone has never been hacked and it is factory unlocked. Any Idea?