On Wed, 09 Jul 2008 10:48:25 -0700, Josh Assing
wrote:

I'm wondering how true that is?

Very true - ask me how I know? :)

Does anyone know if I can make an image (sector
for sector) of the SD card to back it up "just in case" or if putting in a pc
will screw it up?

I wouldn't try it - I'm not a Garmin guy, but I know some who have
your system and have - crash/wipe/burn and Garmin was entirely in
their rights to refuse a new update or card - it's in the users
agreement.

Navionics has the same deal, although it will allow route/waypoint
write. As I understand it, Garmin feels that allowing the write point
will compromise the software and allow for hacking. Then I heard that
the real reason is that the card is so packed full of information,
that there isn't any room for additional data which, as in most
computer things, means that something is overwritten or lost.

Both sound equally plausiable to me.

By the way, did you ever find the solution to your RCM/ZDA problem?
I'd really like to know what it was.