I have a Toshiba Satellite P200 1FZ, laptop, bought in February, 2008.
On three occasions now, after using for about one hour, swirling, pastel coloured, greens, blues and pinks, like clouds , cover the screen. These colours are on all web pages and desktop and on vista, they are straight coloured lines, horizontally across screen.
I have to turn off and the next day they are gone.

StoneyM, July 2008

As you describe, my laptop had the same thing once. It was because of a fail of the lcd panel internal tape wiring. In other words, the whole panel had to be replaced.

Pablo K., July 2008