Had a similar problem on my work laptop and a colleague had it on their father's laptop. In both cases it turned out to be an issue with the graphics chip - nothing to do with the screen at all. Both had Nvidia graphics chips and seems to be a known problem. I know my colleague found a temporary fix for it on the net but don't know what it was.
My work laptop was fixed by replacing the motherboard - not the best option for a privately owned laptop though...
thread might help - especially if it is a Dell that has the problem.
PS - In both cases external monitors worked find and it was still the GPU.
Edited by ian72 (Fri 28-Jan-11 08:44:28)