Problem in live chess

Hello, today I was playing a game on live chess and my opponent played but the move was never shown to me. My opponent claimed that it was my move, but in my screen I saw his clock running and my move last.

This is the game:

http://www.chess.com/livechess/game?id=426841616

When in his screen my clock ran out the game didn't end, so he offered me a draw and when I accepted his move was shown.

I believe the chat is stored, so you (admin) can check the chat for more info.

Thanks.

Edit: To clarify, the last move in my screen was 19...Nxe5. My opponent played 20...Nxe5 but that move never came to my screen.

What browser and operating system were you using?

Firefox 17.0.1 under linux. I don't know about him. The weird thing (for me) is that my time ran out on his screen, but the game didn't end.

Thanks.