I just played a club game and when I came home I put the game into Chessmaster 9000. During the game my opponent was in time trouble and made a few quick checks to get into the next time "phase" (Sorry I'm not sure what you call it)

Anyway I was aware that I could end up drawing through repetition so I made a different move after the position occurred twice. However a few moves later the same position occurred, therefore entitling him to a draw. I might add that he went on to resign about 10 moves later. 

My question is; Is it up to him to realize and claim the win or should it be a draw by default?

It's not a draw by default. If the three move position happens, it's only a draw if one of the players claims it. In tournament play, the player would have to confirm the draw with the arbiter or tournament official, but it would be a draw if it was stated.

also it is a specific set of moves, not any random moves that have to lead to the same position 3 times in a row to give a draw.

I thought could be any moves to claim a draw, as long as all the pieces on the board are in the exact same position at any point in the game (not necessarily one move after another)

Correct me if I'm wrong.

The positions don't have to occur one after the other, but the position has to be repeated three times before a player can claim the draw. He/she does not have to claim it though.

yea that's what I thought, thanks for your comments