I have tried your PhoneInfo4 Example that comes with the PC Connectivity SDK 3.0. It seems to work pretty well at detecting when the phone is and is not connected, as long as notifications are enabled. However, if you disable notification, and then remove the phone, and then press "Get Info", a message box will be displayed which correctly indicates that the phone is not connected. However, if you then reconnect the phone, the system will never discover that it is connected again. Is this a bug?
Is the only reliable way to determine conneciton/disconnection to leave notification enabled?