updated 11:46 am EDT, Thu September 27, 2012
Apple aware of problems
Some users of the iPhone 4S and third-generation iPad are reporting ongoing wireless connectivity problems after upgrading to iOS 6, according to a thread on Apple's support forums. People may, for instance, find the option to connect to Wi-Fi grayed out. Others may be able to turn Wi-Fi on under Settings, but nevertheless be unable to connect to their LAN. Still another group is experiencing trouble with Bluetooth, which may not be able to detect or pair with devices, simply scanning for them forever.
People with the issues say they've contacted Apple, and that the company is aware of the glitches. In the meantime some temproary measures may include resetting Network Settings and changing HTTP Proxy to "Auto"; failing that, extreme steps involve downgrading to iOS 5.1 or performing a device reset and reinstalling iOS 6.
New releases of iOS have sometimes caused Wi-Fi issues in the past. The most common problem though has usually been "weak" Wi-Fi, in which devices will report low signal strength where other devices are fine. With iOS 6, one initial problem was traced to an Apple authentication page that was quickly put back online.