This is the description of the 5.50 version update from the HB website.....
1197c SI Combo Update (version 5.500 - 0 bytes)
Description:
4/27/2011 12:00:00 AM - v5.500 - Corrected phantom tracks issue; Corrected waypoint skipping crashes; Corrected crashes when the Ethernet connection was removed; Corrected communications issues caused when Interlink went offline and correct sonar recording playback issues.
I haven't actually tried the update myself but it is definately an interesting question....Maybe someone can give more info that has installed and tried the update...
Rickie