Some background... I'm running a 280 / 7950 crossfire rig and have occasionally had trouble getting crossfire to work.
Various hardware and software solutions didn't do much. In the old CCC, it would tell me that the bridge wasn't connected when it really was, etc. In the current settings menu, I don't any way to enable/disable crossfire at all.
In any case, I have consistently been able to enable crossfire on my system by changing the registry key "enablecrossfireautolink" from 0 to 1 and then rebooting. It seems to work perfectly fine after that, even upon subsequent reboots. The strangest part is that the registry key goes back to 0 afterwards, so I'm not really sure what's occurring. Obviously something is not working as designed here. You probably don't want users tweaking with the registry like that.
This isn't really a pressing tech support issue since crossfire seems to be working, but I'm really curious what's going on here.
My specs in case it's pertinent to the question: