I've had this issue since I've had my phone in October. My wifi displays one bar up at the top but in settings says full bars. I've tried so many things and my roommate just got an iPhone 5 for sprint for Christmas and hers works perfectly!!! I can't tell if my wifi has a problem or not. I'm trying to see if anyone else has had this problem!??? 6.0.2 didn't fix this either like I had hoped and waited for it to do.