I recently upgraded from the stock Nav Disc 3.0 that came with my '05 EXT to the Nav Disc 4.0 directly from Cadillac. Now, everything (restaurants, stores, addresses, etc.) is about 300 yards off. In other words, if I am physically in front of a restaurant, it shows on the NAV screen about 300 yards down the street, not always in the same direction. Has anyone else seen this problem?