Maybe i can clarify as i am having the same problem. I use 3 screens connected using eyefinity for a 6400×1080 display. my middle screen is a 2500×1080. so when i turn on eyefinity, the tobii calibration sets each side pink dot on the side monitors. as a gamer we usually use the side monitors simply for periphal vision. so if i can have my display set up for wider than the tobi calibration display is set then it would work. currently i can not change tobii calibration display to be smaller then my desktop display.
sorry im at work at lunch, if you need more clarification i can write this better later.