James and I discovered a strange edge case a few days ago that I figured I’d blog about. The long story short is that the iPhone will auto-join hotspots with pay portals, such as at Starbucks, Kinkos, or the airport. The problem is that the iPhone thinks the network connection is active, but it can never get valid data back from the server.
One effect of this you may have noticed is that when you go to get your email in the airport, the spinner just goes indefinitely. This has gotten me a few times, and I have to remember to turn WiFi off.
More importantly, if your program doesn’t handle this effectively, bad things can happen. For an example, with the MobClix ad library you temporarily see the login screen from the ad bar and then after twenty seconds the app crashes. Whoops.
In any case, be careful.