Whenever I leave a WiFi network, I need to restart my iPhone in order for it to successfully start using the Edge network again. Five bars and the little E show that I am connected to Edge, however, without the restart, the iPhone simply doesn't connect to anything (Mail, Safari, Contacts/ActiveSync Directory search). The little circle spins and spins, the phone heats up, and the battery drains quickly as it continually attempts to negotiate network access. Once I restart it, Edge is back to normal (meaning painfully slow, but working). I jump on Wifi several times a day, so I am restarting my iPhone several times a day. This started happening recently, I think with either the 2.0 or 2.01 udpate.