If you want to use two displays you have to disable SLI. This you can do in drivers from version 71.84 onwards.

Nvidia recommends using Nview to have a picture on two screens. The company tried to defend its inability to work under two display mode by saying that most games work in "DirectX full screen exclusive mode". They do it to prevent you pressing F1 by accident and getting the help screen while you're playing.

Still, you can override this quite easily in most of the cases and some games like the extremely-popular Dark Ages of Camelot can work on two screens if your graphics card will let it.

So at least for now, if not indefinitely, SLI users will have to play at one display only till Nvidia changes its mind, and in the case that Nvidia can actually fix it. µ