This is must be a bug, I set my Sprint to travel 1 hour and 40 minutes in sublight, came back home and got absolutely no EXP for it and didn't even get an General Event about it. I asked a friend though and he didn;t encounter any problems.
It's a slight 'bug', if you exit and re-enter your ship you have to make sure you are still in 'pilotted' mode (check your inventory and make sure the mouse icon is in the top left corner or the ship image)