GPS Coordinates Question?

With 4 decimal points, you're down to degrees, minutes, and seconds of longitude and latitude (there's 60 minutes to a degree and 60 seconds to a minute). So, that's a location within a 100 yard radius. With the 5th decimal place, that's a location within a 10 yard (30 foot) radius. And, the GPS probably just simply can't resolve down to a 1 yard radius, which is what you would get with that 6th decimal place.