After applying the Mac OS X 10.4.8 Combo Update on an Intel-based Mac, older versions of QuickTime Player may fail to handle some content as expected. In this situation, movies display only blank, white video, and no audio is heard. Image files may also appear as blank in QuickTime Player.
Update QuickTime to 7.1 or later. You can get QuickTime updates from the QuickTime web site, or by using Software Update, available under the Apple menu.