I just solved this problem. Like others, this problem happened to me immediately after receiving a new Dell Inspiron N4050 laptop. After four hours search this problem on Google with, I broke down and contacted Dell technical support. The support agent downloaded and installed a new video driver
and a new BIOS update. This fixed the problem.
Needless to say, I am glad the problem is now solved. But I am angry I wasted an entire day on a problem that never should happen with a new PC.
Hope this information helps someone else.