You set the Colors setting on the Display Settings tab in Windows Vista to a 16-bit color setting.
You have the Bubbles screen saver selected to run.
However, when the Bubbles screen saver runs, the desktop background is not displayed as expected. Instead, the desktop background appears as a blank, black screen. For example, you experience this symptom when you set the Colors setting to Medium (16 bit). You do not experience these symptoms if you use a 32-bit color setting.
This issue occurs because Windows Aero functionality is not enabled when the Colors setting for the display is set to a 16-bit color setting. Therefore, when the Bubbles screen saver runs, the desktop background is not painted.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about Windows Aero, visit the following Microsoft Web site: