Crossfire hurts when its enabled. Crossfire cables being plugged into the cards doesn't mean crossfire is enabled. I have the bridge plugged in on my main pc but have crossfire disabled in the driver control panel. Works just fine...
When I set it up with 4 cards Windows 7 wouldn't detect the other cards with crossfire disabled.
Anyway people should use crossfire cables not dummy plugs I get it, lets move on. =)