Yeah - I noticed that too.

Tested the barbarian scout in last revision from SVN. The scout runs around removing the black areas of the map around him. Once everything in nearer radius around him is at least revealed, the scout does nothing, sitting on his food. I believe this is by design, I couldn't find any problem. Does he have still black map areas near around him when he stops scouting? The scout is not there to remove fog of war, but to remove black map areas. The return=skipped is apparently not necessary.

I have hacked the scout file on my machine, and have him out scouting for ten minutes. It would seem that the "scout" problem is run on random parameters - sometimes he is out for 30 seconds, sometimes for the full ten minutes.

Additionally, and obviously depending on whether there is unscouted land, he may only go out once, or perhaps two or three times, but to date he has not gone out until ALL black land has been scouted. His frequency of scouting missions, and the length of them, all seem completely random.

On a personal note I don't think the scout is a good ROI - even when hacked.