Answer
This question was answered on November 25, 2007.
Much of the information contained herein may have changed since posting.
It sounds like a video card driver issue. Find out the manufacture of your video card and go to the manufactures web site and download the latest drivers for your card.
This should fix any issues you have.
Also make sure that your color quality is set to 32-bit
to do this right click on the desktop and go to properties click the settings tab and change the color quality to the highest available, should be 32-bit.