Datacolor User to User Support Group.

I've now received a reply to my enquiry to the Datacolor Europe support team....I'm based in U.K.
Basically they say that the video card would need two LUTs in order to calibrate the two displays and this would need a modern high-end card. The only way to find which cards have two LUTs is by contacting the manufacturer because it's not obvious from looking at the card or (I think) its specs. As you said earlier in this thread.
So I guess it will be simpler to stick with calibrating one display and using the other as a work area.
Thanks to you, and kindest regards.
Julia