Consider the following scenario:
- You have Windows Vista installed.
- Windows Aero is enabled.
- Your are using a interlaced video resolution for your monitor (i.e. 480i or 1080i).
- You rotate the display to 90 or 270 degrees, known as Portrait Modes, through your display software or Windows Display Properties.
Rotation in Windows Vista with interlaced portrait modes and Aero enabled may not work at the rotated angles mentioned above.
Microsoft has resolved this issue in Windows 7.