I recently upgrade my computer from a single geforce 260 192 and i added an xfx geforce 260 216. It has worked fine for the last week but now i have been getting this random freeze up when close a game and launch another game. A few times i have received a page file out message from steam and I also get an error saying my graphics driver has crashed. All my games seem to be affected it doesn't matter which.
your two graphics cards aren't exactly the same,
so they don't play nice in SLI
you'll have to just use one card as a physics card and the other as the video card for it to run smoothly (unless NVIDIA comes out w/ a driver update that fixes that, but i doubt it)