Wow, that's odd! Any heating problems? Did it just power off or something? Mine's done that once or twice before, with no warning.
That's the main culprit with mine...I think...seeing as even the sides of my touchpad get hot, as well as the keys themselves.
And half the time it even happens while I have the standing fan blowing at it! Plus at its worst, mine will lag on scrolling, typing, clicking, showing a drop-down menu...it's crazy.