Little question; did you check the CCC setting to make sure CFX was turned on? Sometimes the damn thing doesn't turn on by itself (or turns itself off after a driver update).
I use Radeon Pro to check if CFX is really working (you can see the load each card is getting)
Also, I'm not 100% sure if it's true, but did you use both CFX links or just the one? I haven't even tested myself, but there are people that sware that using both links help with load or is sorta of a backup... I used both, haven't had issues so I left them there, but chances are you don't need both... but you never know.
i used amd system monitor to check if CFX is working and only one card works. my CFX does like to turn on and off randomly but i check it before i play any games. I also have two CFX bridges connected to my cards.
ok i ran single player, i set ccc to show the crossfire logo in the corner and ran gpu-z. crossfire was working. i reinstalled my drivers and set them to defualt. when CAP was set to BF3 crossfire would not work. while i was playing i was getting around 60 FPS with the medium settings 1650x1050. only problem was it would some times dip to as low as 17 FPS then jump up to 70 FPS. is this due to a bottleneck in my system?