Windows Server 2008 or Windows Vista Service Pack 1 (SP1) may not display tooltip text correctly if the text contains both alphabetical characters and Japanese characters.

When you watch a video in Windows Vista, video performance may suddenly be reduced. For example, you may notice lost frames or other poor video performance.

This problem occurs if the following conditions are true:

• The system does not support Windows Aero. For example, the computer is running a version of Windows Vista that does not support Windows Aero, such as Windows Vista Home Basic. Or, the video hardware of the computer does not support Windows Aero.
• The video window is partially covered by any of the following Windows elements:
  • Windows Sidebar.
  • The Windows Start menu.
  • A tooltip.
  • A software pointer that has shadows.
  • Any window that has rounded corners or other transparent elements.
  • A window that has shadows.
  • A sprite that has transparency elements or shadows. A sprite is a two-dimensional image or animation. For example, some Gadgets for Windows Sidebar are sprites.

  Video performance decreases only when any of these elements partially cover the video. When the elements no longer partially cover the video, the video plays as expected.

  The poor video performance may be more severe on computers that have slower CPU hardware. Other factors that may affect this problem are the display resolution, the random access memory (RAM), the graphics processing unit, the memory bus, and the drivers.

Consider the following scenario. One of the following conditions is true:

• Your computer is running a version of Windows Vista that does not support the Windows Vista Aero theme. For example, your computer is running Windows Vista Home Basic.
• Your computer is running a version of Windows Vista that supports the Windows Vista Aero theme. However, the video hardware of the computer does not support the Windows Vista Aero theme.

You watch a video. You move the mouse pointer over an area of the video playback program that causes a tooltip to appear. For example, a tooltip appears in Windows Media Player when you move the mouse pointer over any of the following video playback controls:

• Play
• Pause
• Fast forward
• Rewind

In this scenario, the video playback performance may be reduced suddenly. Additionally, you may notice lost frames or other poor video playback performance.

Note: You notice the decrease in video playback performance only when the tooltip is present. After the tooltip disappears, video playback resumes as expected. The poor video playback performance may be more severe on computers that have slower CPU hardware.