"If you see that your opponent has been able to move a piece back to a square that it came from in the previous move, then write to us. We will back the game up and ask that your opponent make a different move." The above is stated in the rules at the other site mentioned about the movement bug.
(hide) If you need to find an older message from the selected user, click on his Profile and use the "show this user messages" link at the page top. (konec) (show all tips)