iPhone 5 tethering, device hard to discover, normal or a problem?
You should verify which software level you're on. 6.1 isn't available to the public yet. iOS 6.0.2 specifically fixes a Wi-Fi bug (Apple doesn't say what the particular bug is, but it affects Wi-Fi). Check to make sure you're not on 6.0.1. If you are, upgrade to 6.0.2 and see if the problem is resolved.