I don't know what to tell you, unfortunately; I have Flip4mac installed too, but as I said it looked like a Quicktime stream when it launched the Yahoo player, so Flip4mac should be irrelevant anyway. I had no trouble at all. (I'm running OS X 10.5.5; maybe it's something different from you. I don't have anything unusual installed at all.)
Watching on Gameplan now anyway.