Yes, draw because you had a lone king. If you had had one more cheap pawn, you would have won.
The "insufficient material" rule implies that in case some one runs out of time, we imagine that if he made the very dumbest moves for the rest of game but the opponent could not win, then the game is a draw; otherwise the out-of-time player is considered lost.
So in case you have a lone king, whatever your opponent does you cannot deliver a check and mate him/her, so the game was a draw.
If the game is literally not winnable then you can never get a win unless the opponent resigns (which would be hilarious! 
); irrespective of the clocks.
I understand the insufficient material rule. If neither player has sufficient material, a draw is automatic since a mate isn't possible. In this case he did have sufficient material and a mate was possible, he just didn't do it in time. It just seems like the time controls should take precedence here.
lets take the following diagram for example.
I think everyone would agree that this is easily winning for white, however if he runs out of time first, black wins. With perfect play by both parties white should win, just like in my game. With correct play my opponent should have won.
If insufficent material didn't draw, things would start getting stupid. e.g. your opponent forces you to prove that you can make 50 king moves in a king vs king endgame with 10 seconds on the clock.
Maybe I am mistaken, but I believe the reason you got a draw was that 'you' did not have enough material for a win. Not that your opponent didn't have enough material for a win.
I guess I was just confused about which takes precedence, the insufficient material rule or the clock. If you go by insufficient material then no I could not win, but if you go by the clock I won.
Maybe I'm just being a whiner because I thought I won. Oh well, now I know for next time.
You could not win because you did not have sufficient material. Your opponent could not win because he ran out of time. Since neither of you could win, the result is a draw. Sounds logical to me.....
Had you been the one to run out of time, your opponent would have been awarded with a win because he had sufficient material to mate you. You may be a bit confused because there's multiple rules here. The "insufficient material" rule you mention (the automatic draw when neither player has sufficient material) has nothing to do with time controls or running out of time. It is even true for games played without a clock. The rule that declared your game drawn is a similar one that is used in timed games.
Just be happy that you didn't lose, which you should have had the clock not saved you.
You could not win because you did not have sufficient material. Your opponent could not win because he ran out of time. Since neither of you could win, the result is a draw. Sounds logical to me.....
when you say it like that it makes sense.
I played a game yesterday where I had only my king left, and my opponent had his king and queen. Well he ran out of time so I assumed that I won, but to my surprise the window popped up saying draw by insufficient material. Is this correct? Is there some rule I don't know about? If I don't have sufficient material to mate my opponent does that mean he cannot lose on time?