My experience after flashing the update is that the Navicore software has to be installed again [navicore_n800_armel.deb}.

The licence key does not seem to be disturbed by the process and was automatically available for activation i.e. just OK the dialogue box when requested, the cd key is already in the text box ready for confirmation.

Though bearing in mind the inconsistencies we are observing with this update it may be different for others.