I think you misunderstood my post, callback number is not the problem. Launch your GC Dialer and call any number (a number you can answer) but make sure Gizmo is not running nor is rtcomm (your presence settings should show your are Disconnected )and see what happens. Now do you see the point I was trying to make? GC Dialer should have a setting that the user can select Gizmo or rtcomm as the default call back phone application.