A few weeks ago I received my new Samsung Galaxy S3 - GT-I9300. This is an International, unlocked unit. Everything was working flawlessly for several weeks, including stable WiFi connectivity, until Sunday when an OTA upgrade was automatically downloaded bringing Android to version 4.1.1. The upgrade appeared to install successfully, but the next day when I turned on the phone, the S3 would not connect to WiFi. When I looked at the S3 WiFi panel, the network SSID entry displayed "connecting" and then "disconnected" until the next scan occurred. The S3 continuously displays "connecting" and then "disconnected." Turning WiFi off and on again has no effect. I tried the "Forget" WiFi option, re-entered the logon info, but that didn't help either. I pulled the battery, waited several minutes, and reinstalled the battery also without any difference. My wireless router (NetGear WNDR3300) is working perfectly, and none of the 20 other network devices have any problems connecting. Only the S3 is having problems since the 4.1.1. upgrade. As an experiment, I unplugged the router's power connector and plugged it back in. Magically, the S3 immediately connected to the router! Early the next day, the phone still connected to WiFi without a problem. Then, later in the morning, the same thing happened - no WiFi. Again, I unplugged the router's power and plugged it back in. The S3 then immediately connected. I performed a factory reset and wipe on the S3, but the same thing continues to occur every day with Android 4.1.1. Since this is only happening on the S3, I assume it's the result of the 4.1.1. upgrade. Has anyone else has this problem, and if so, were you able to resolve it? Any suggestions would be greatly appreciated?