Re: 7X13 The Name Of The Doctor(Grading/Discussion)(SPOILERS!)
There is nothing wrong with the navigation system on the Doctor's TARDIS. It works perfectly fine. It's more or less stated that the TARDIS overrode the destination to take the Doctor where he was needed rather than where he wanted to go.
On the continent of wild endeavour in the mountains of solace and solitude there stood the citadel of the time lords, the oldest and most mighty race in the universe looking down on the galaxies below sworn never to interfere only to watch.