what do i need to do? used draw button but it offered draw.

it probably wasn't a true three-fold rep then.  sometimes, they can trick ya.

maybe post the game and we'll see how it went.

Using the draw button is correct. If the position has really occurred for the 3rd time, it will claim a draw.

draw accepted.  something may be wrong it was three-fold when i hit button. thanks for the help

Post the game?

Looks like this is the game: http://www.chess.com/echess/game.html?id=47360172

Definite threefold repetition.

I had a similar experience once, and figured I must have been doing something wrong. But I think this may be some kind of bug--you definitely had a threefold repetition, so if you hit the "draw" button and it didn't claim the draw but instead waited for agreement, then it seems there's a problem...

The first time Black played his Queen to e5 on move 13 does not count since White's subsequent move changed castling eligibility.

Where the position is the same three times would have occurred on Black's 18th move if Qe5+ was played a fourth time.

Edit: Not 18...Qe5+ but 18...Qg5+.

castling eligibility must be the reason. thanks

I guess I've misunderstood the castling eligibility requirement. I was thinking "after each black queen move, the king is ineligible for castling, so castling eligibility doesn't change."

Should I instead have been thinking "On white's move previous to the first queen move, white could have castled, but on white's move after the first queen move, white can now never castle, so eligibility changed"?

Not legal versus not eligible. Being in check means it is not legal to castle, eligibility would have remained intact if the King did not move.

FIDE rule  http://www.fide.com/component/handbook/?id=124&view=article

"9.2 The game is drawn upon a correct claim by the player having the move, when the same position, for at least the third time (not necessarily by a repetition of moves): 

a. is about to appear, if he first writes his move on his scoresheet and declares to the arbiter his intention to make this move, or

b. has just appeared, and the player claiming the draw has the move.

Positions as in (a) and (b) are considered the same, if the same player has the move, pieces of the same kind and colour occupy the same squares, and the possible moves of all the pieces of both players are the same.

Positions are not the same if a pawn that could have been captured en passant can no longer be captured in this manner. When a king or a rook is forced to move, it will lose its castling rights, if any, only after it is moved."

Note: On the site the player moves then tries to hit the draw button before the opponent moves and spoils the draw.  http://support.chess.com/Knowledgebase/Article/View/40/0/how-do-i-claim-a-draw

"Once the position has repeated three times, make your move then click on the "Draw" button. This ends the game as a draw."