That's unfortunate - as I say my Geotagger N3 has worked, and is working, flawlessly with my D800. I also have a Phottix GPS which I used to use with my D7000 and now use it for my D600. Both 3rd Party products, both working on different cameras without problems. I had a Nikon GPS-1 with my D90 and sold it with the camera. It also worked perfectly, but I think the Geotagger seems to acquire much quicker and of course has the compass. No complaints. I guess every manufacturer can have bad copies of a product.
When words become unclear, I shall focus with photographs. When images become inadequate, I shall be content with silence. - Ansel Adams