Not updating the score .... I remember playing a Polish guy in quarters at a seniors tournament in Bol, Croatia. I was the top seed (or 2nd, can't remember) and he started like a house on fire. Changing the scoreboard after every game instead of waiting for the changeover as is normal practice. Anyways he was 3-0 up first set and then I decided enough is enough. Won the next six games and he never went near the scoreboard again and it stayed fixed 3-0. He played well the second set and won it 6-4. So, set-all. Then it happened, for the first time ever, and never again since... after winning the final point of the second set he came to the net with his hand outstretched and said thanks for the match and claimed he won it in 2 sets! Weird stuff and trying to pull a fast one. He refused to budge and eventually I called the tournament referee as this was a crazy situation with a very voluble Polish guy. Just before the ref stepped in the court he I saw him speaking to a few spectators. So, he arrives and asks us what is going on. Polish guy says he won the match ... ref then asks him why his Polish friends outside the court say it is set-all. Funnily enough my opponet kept arguing for another ten minutes before eventually realizing that he had to play the 3rd set! All ended well and I won the final set. Eventually ending winning the tournament even after breaking my left arm during the first point of the second set - but that is a story for another day!