Couldn't decide to post this to WiFiRUSH or CoovaOM but the result is the same.
When using a captive portal to authenticate with username, the iPad cannot connect. I choose the available network and immediately get prompted with the splash page "Wireless Hotspot", then bounced to the Username Password page. When I enter a valid username/password, and click Login nothing happens. It just hangs and eventually disconnects the iPad from the wifi network.
Same thing happened with wifirush.
What could it be that's preventing an iPad from accessing the captive portal?
I know several of my customers have iPhones, iPad's and iPod Touch and assume they will all have this problem if I switch to a captive portal.