KNA-DV4100 goes nutz

I own a KNA-DV4100 and its been connected to the KVT-815DVD for over two years and no problems. Until last Friday 10/6/06 the navigation went crazy. All of a sudden the gps could not keep track of the current position, or if I was stopped at an intersection the screen marker keeps on going off into the wild direction, and while using a simple destination it does not reroute fast enough more than 30 seconds, or the screen marker gets to the intersection before the car does. I have checked the diagnostic screen menu # 014220, gps says its tracking 7 to 8 satellites, and vehicle info is transmitting speed sensor info Kph, mpk, and look within range from the speedometer to readings coming from the unit. I have tried reset a couple of times now since last Friday and tracking navigation is unreliable at best in Clear sky?s Please Help, I rely on the navigation to be accurate.

I just purchased the updated DVD but I haven?t received it yet.
But what would cause it to go so wildly out of control? Something going on with the GPS satellites? Please advice