I am in South Florida and I have the same problem with two different phones. The first phone I received worked right out of the box but had a bad speaker. When I received the replacement phone I receved the "unkown error". I figured that I could switch back to the first phone but I had already prepared it for shipping back to Sprint by doing a hard reset. When I switched the service back to the first phone I received the "unknown error". I have spoken to many people at tech support and it still does not work. Their only solution is to send me a third phone.