this is a new problem that is a real disaster for a photographer like me. The unibody 15 under mac os x does not support two different color spaces on two displays. I struggled with false colors on my external monitor over one month and then discovered this problem by reading different posts. This is really a horrible problem and really makes me and other photographers want to switch to windows. Before shipping the unibody units, didn't anyone at Apple check the colors as they appear on an external monitor? It's incredible, but I think that if I was employed at quality control at Apple a lot of problems for photographers and video editors would have been corrected already. I would never allow some crazy problems like this to go out in the open. This makes me think that I wasted over $2000 for my Unipro. Apple never mentioned that the system would show false colors when used in dual display mode.