- Displaying a simple "unable to connect" message upon attempting to connect.
- Showing a tick against a particular network as if it has connected, but failing to show the Wifi icon in the status bar and refusing to transmit or receive any traffic.
- Transmitting and receiving traffic at such a slow rate that it takes several minutes to load a typical web page.
- Dropping the connection suddenly and unexpectedly.
My iPhone 3GS running 4.2.1 appears to suffer the same problems, while users of other devices appear to be able to use these networks with no problems from the same location. This effectively demonstrates that the latest version of iOS is the likely source of the problem.
I don't necessarily expect to hear any magic quick-fix solutions as Wifi problems on iOS 4.2.1 appear to be acknowledged by many end users, but I would be interested in hearing others' experiences of how widespread these problems are, and I also believe that this should serve as a warning to anyone considering purchasing an iOS device for use with public Wifi networks while travelling.