Ever since the day I first posted this issue the navigation system has worked flawlessly. Initially there was a big greasy fingerprint on the NAV DVD which I removed with some plastic polish. But it has acted up since that cleaning. It seems to have a problem with excessive humidity. Here in Mississippi it gets very hot & humid and all 3 times I had the "DISK ERROR" it was excessively humid outside.
I will inform of any further developments. On the bright side my wife can get anywhere now with this advanced navigation system. She is not much of a natural navigator but all she needs is a street address to key in and the truck does the rest. Pure magic.
