For anyone who has a K1600 running a Nav IV and has suffered from the device dropping a current route when the ignition is turned off, help is apparently at hand through the latest software update.
Changes made from version 4.50 to 4.70:
Improved the speed of TrackBack route calculations.
Fixed an error that caused the device to freeze when importing routes from gpx files.
Fixed an error that caused a missing key on the Arabic keyboard.
Fixed an error that dropped street names with the Czech text language on the map.
BMW Nav IV only: Fixed an error that prevented the page button from working properly on the Fuel setup page.
BMW Nav IV only: Fixed an error that caused the previously active route to deactivate when the vehicle was restarted.
Changes made from version 4.50 to 4.70:
Improved the speed of TrackBack route calculations.
Fixed an error that caused the device to freeze when importing routes from gpx files.
Fixed an error that caused a missing key on the Arabic keyboard.
Fixed an error that dropped street names with the Czech text language on the map.
BMW Nav IV only: Fixed an error that prevented the page button from working properly on the Fuel setup page.
BMW Nav IV only: Fixed an error that caused the previously active route to deactivate when the vehicle was restarted.