Does the 798 get the GPS signal four times a second?
I remember on my 1197, that the 4.700 update went from
once to four times a second.
Diamondback:Does your unit have a clear view of the sky at all times?
Note: the human body can block GPS signals.
Depending on the angle from the unit to the satellite(s),
and if you are sitting or standing in front of the unit, it may make a difference.