Me too.
Something like that happened in four of my games, most recently in:

http://www.youplay.it/play/bm_GameMove.asp?GameID=109958&UserID=Heggers

I input a move and it takes me out of the game and displays some kind of error message - The problem was that I used my "server history" to go back, and so I inputted the same move twice

Also, the link I have "back to games list" (is that it?) isn't working anymore.