My HP laptop would do that also... and it got worse with age. I believe it happens when the computer gets too hot. The fans on a lot of laptops are not large enough to cool it, and it is especially bad when the computer is working hard such as while watching a DVD or playing a video game. There isn't a whole lot you can do. I would elevate mine using two VHS cassettes (make sure the vents on the bottom of it are exposed) and aim a fan at it. They also sell special fans that you set the laptop on. Also you can buy some compressed air and blow the dust out of the vents. I hope this helps.
John, June 2008
