Captive portal + iPhone auto-join

[IanC]

Hi folks,

Ever since Apple released iPhone version 3.0 firmware, Ive been seeing
a recurring issue like so:

- iPhone users can connect as normal to an AP, get its address via
DHCP, arrive at the captive portal, sign in as normal and browse.
- Anytime after that initial successful session, they can get a valid
address via DHCP, but then the iPhone browser grays out with a
spinning "loading" message that never goes away.
- User can then click "forget this network", turn off wireless, then
turn it back on and viola, it works again..for one session.

Ive never seen this behavior with anything other than a Chilli
controlled network, has anyone else seen anything like this with
iPhones?

--Ian