You don't actually scratch. You just click. If you get to where you can see the leprechaun, I believe that you are actually "in" the game. If I'm remembering wrong, though, if you try to click on a square and the game is full, you will get the message that, if I recall correctly, "the maximum number of games have been played".

XP, eh? I don't know much about that, but I'm sure others do. I wonder if you have popups disabled? Maybe disable them and see if that helps? I don't KNOW if that will make a difference, but maybe...