I use my macbook with multiple applications open: photoshop, Firefox, Nikonnx software; lots going on. And I use it with capture control to capture images. For over a year it sometimes comes to a halt - and typically moves slow. Rainbow ball. Arghhh. Not always though. I wondered if it is just low on RAM but I watched the activity monitor and the RAM graph is green. Both RAM slots are full with 2GB each. Was wondering about switching to 4GB each but with the activity monitor not showing RAM as an issue I am not sure if that is the answer. I update software all the time. Any suggestions what the problem might be?