I have a Macbook (older version), and for some reason lately (the last week or so) whenever I've been watching movies, the fan's started spinning up like crazy (using VLC mostly but also QT). It seems to be louder for bigger files (I just put on a 45 minute AVI and it's up to ~6200 rpm). After I close the file, the fan doesn't stop until I restart the machine. It doesn't seem to change depending on where the monitor is (desk, bed, etc.). Also, from around the same time I've had this issue that when I detach my external monitor and close up the Macbook, then reopen it (without the monitor, like on my bed) and try to play a movie, QT or VLC or whatever will show scattered bits of my desktop and then not play the movie file properly. Any idea what's going on, or what to do??