Is yahoo always correct with their NHL scores? I know that for NCAA Bball, sometimes they reverse the score or get them totally wrong. It's caused me to have minor heart attacks in the past!
NEVER trust yahoo 100%. They've put up some pretty ****ed up scores sometimes in the past. Still, I have found them and USATODAY.com to be better than most out there.
I use ESPN and open a separate "game update window for each game I'm following. You can set the refresh rate of each window and it gives you fully updated stats at each update (not always for every refresh though).
ESPN is great for MLB you can get play by play updates with a diagram of the field and player positioning (also auto refresh).
Also NHL.com provides pretty good score updates with an option to listen to the games on local radio if you have a fast enough connection.