I want to echo Snodderly. You definately don't need to leave the board.
Only you know when it is time to close that door and only you know what you are able to forgive and live with. Each of us has our own "deal breakers".
She is also correct in saying that the MLCer, rarely disappears entirely from your life. I love the analogy that they are like children who are always with you and I can relate to that as well.
"Acceptance doesn't mean resignation. It means understanding that something is what it is and there's got to be a way through it."--Michael J. Fox