I have a 2007 s-type 4.2, my problem is this. I have an updated Nav disk as of 2015, when I go thru Jacksonville FL, the nav loses it's mind. It puts me all over the place, even the ocean. If I turn it off for an hour, it usually come back normal. For some reason this only happens when we head down to Florida. Any body have any thoughts.
Thank you. Ken

 

What happens with an older disk?