Here is what happens since yesterday. At first, when I first turn it on, it is obviously cold. Then, about half an hour, it becomes insanely hot, even the left speaker grill feels hot, then, I prop it up for a while, and for the rest of the day, it runs quite cool? Enclosure base based on iStat Pro is 40deg C when its hot, and drops by 5deg C later. Does anyone know what is causing this? The activities I do are pretty much the same, just browsing the web.