The Kibitzer's Corner at chessgames.com has this comment from Poisonpawns: "Here is a game I played against West in 2006. I will never forget, he would not shake my hand after the game. I thought that wasn't cool. When he had beat me a few years before, I shook his hand and went over the game."
On January 4, 2012, I e-mailed an administrator alert to chessgames.com which reads, in part: "I have no recollection of ever refusing to shake an opponent's hand, either before or after a game, in nearly 40 years of tournament play. As a chess coach, I teach my students to shake their opponent's hand, regardless of the outcome of the game. Very often when I resign a game, my resignation takes the form of a handshake."