Draw: Insufficient Material??

I played this game:

I was about to win on time then this came up:

Draw: Insufficient Material 0.5 - 0.5.

But there was sufficient material!

What should I do?

When a player runs out of time he loses the game if his opponent has got pieces enough to win "regularly", i.e. he has got even a theoretical chance to win regardless of the time. It means that if White runs out of time in the below position Black will win.

Black can promote his pawn and win, theoretically of course. But you had your king only which means you were not able to checkmate your opponent. Consequently, the draw is a correct result.

You cannot win on time if you do not have enough material to mate the opponents king. So e.g. if you have only the king left or a lone knight with the king, the game will be drawn if your opponent runs out of time.

OK.

http://support.chess.com/Knowledgebase/Article/View/40/0/how-do-i-claim-a-draw