well that just stinks! i'm one of the people that prefer the dual GPU on a single card. i did my first crossfire setup with 6970s and it's unbearably loud under full load. my 5970 that i replaced never got even a fraction as loud as these do.
i'm definitely getting a single card dual gpu setup though. probably nvidia this time so i can start rocking the asus 120hz as my primary display. i'll toss one of my *old* 6970s in my wife's pc so she can deal with the loudness of crossfire, then use the other as a paperweight.
it's a shame nvidia doesn't loosen up it's sli compatibility like amd has. i like having the option of adding another single GPU to a dual GPU card.
How are the 6970's arranged in your case?
The AT HD6970 review mentioned noise and temperature problems if two cards are right next to each other.
http://www.anandtech.com/show/4061/amds-radeon-hd-6970-radeon-hd-6950/24
http://www.anandtech.com/show/4061/amds-radeon-hd-6970-radeon-hd-6950/11