I edited your post, just so that it was clearer that you had resolved the problem.
If I were to guess, you were running initially at 256 colors, which will cause the contour display to appear as you described. Once you changed the settings (and rebooted) to a greater color configuration, it was fixed.
Had the problem persisted, I would have recommended video drivers, etc.
- Ed Lecuyer
Manager, Quality Assurance and Technical Support