said by Moffetts:My iphone 5 doesn't have a problem connecting to wifi after waking back up but it does have a problem with my school's captive portal. Usually I have to reboot my phone after the network kicks me off for inactivity (30 minutes of idle, I think). It will connect but it wont bring up the CP page.
My Evo never had issues with that.
I've seen similar issues with both hotel WIFIs as well as even private networks. A couple of things to try would be to go into WIFI and turn it off and back on. If that doesn't work, then go into WIFI and see if the actual network you want to be connected to is listed. If so, just tap it once to force a connection. If you get an error that it won't connect, then that's usually a firmware issue with whatever WIFI network hardware they're using. If the behavior is as such, maybe try to report it to your school's IT dept... find someone higher up than the regular tech guys if they seem unconcerned with your issue. They certainly won't be at the level that is required to apply such fixes anyway if it's a firmware problem with the equipment. Good luck and I hope you can get it fixed soon.... for yourself and I'm sure others at well.