I have notice that as well. It only takes all the cpu usage when it not waiting for you. (ie, minimized and rendering) Here is my theory. Poser does that by design. It is waiting for you to move something or load something. It takes all the cpu time checking to see if you have moved something. It also has to continully update the screen with its very memory intensive graphic interface. It would take all the cpu usage for faster response time. That is my theory.