DVD movies are shown only if a display is connected to the factory-installed video card. If a second video card is installed in the computer, and a display is attached to that card, movies will not appear on that screen.

With a display connected to a separate video card and none connected to the pre-installed ATI video card, the DVD video software opens and presents a video window. However, when a DVD disc is inserted, the window disappears. The application is still running but it is routing the video signal to the ATI card.

The only way to view a movie is to use the pre-installed ATI card. Because the DVD decoder is a daughter card attached directly to the ATI 128 Graphics accelerator card, it does not allow the video window to be moved to a second display or extended desktop.

This issue may also affect Power Macintosh G4 computers with additional video cards installed. The error message may indicate a software failure, but you should verify that the menu bar is on the built in factory card and that the video is being directed to that card instead of the additional video card.

Article 30887, " Power Macintosh G3 (Blue and White): Apple DVD Player Cannot Open " contains information on other DVD error messages.