My Airmap 300 does the same thing. I've just assumed it is related to
losing its fix on the sats once in awhile. I agree it is annoying, and
I'm thinking of getting a new handheld GPS because of it, except of
course I hate spend the $$ if this is something that happens on all the
handhelds. What is anyone's experience with this? Is it more
prevelant with some brands?