Hi
It seems that driving stats require you to use a driver. I just played a round without a driver (forgot it in the club house ...) and no stats were collected. If they weren't counted at all it would be sort of ok, but when I play with a driver but select another club at the tee it counts as a miss, and that's definitely not correct. (I also think my driving average went down after the driverless round.)
This is how pgatour.com defines driving accuracy: "The percentage of time a tee shot comes to rest in the fairway (regardless of club)".