i had to uninstall the NAV2002 in order to work the NAV2003 correctly. my build is 9.00.35 and it still works fine. however, in the main menu it says: "Externel Test Build".
i installed nav2003, which later displayed as an external test build. as one betaone member said, i had to uninstall previous versions of nav in order to install nav2003 without errors. but today however, after updating a nav component i selected to restart later. after restarting it started giving the same error message over and over which asked to restart the computer.