if the game is under 4 moves (2 each) old you'll still have a delete symbol there. You can't claim a win on a game that's only just started because there is no way you can have acheived a decisive advantage. Other than that, I dunno why.
EDIT -- yep, that game has only had 2 moves made. The fact that your opponent has only ever made 2 moves & hasn't moved since the 2nd July suggests that he won't be comming back. Deleteing the game might be the best plan.