I am currently having this issue. I just bought my 2013 C-Max today as a certified per owned from a Ford Dealership in PA. I live in Baltimore, MD and noticed it having this issue repeatedly on the 110 mile trip home. I will have to call the dealership on Monday to see what they can do about it. I have the A5 SD card and the latest Sync update. This is a bit frustrating as I live in a big city I just moved to and I need the GPS to be accurate. It was raining all day, so maybe it had something to do with it. I am glad to hear that this is a known issue though.