Apple Thoughts: Apple Rolls Out Quicktime 7.5.7

"This update is recommended for owners of MacBook, MacBook Air, and MacBook Pro with Mini DisplayPort. The update addresses an issue where some standard definition purchases from the iTunes Store do not play on some external displays."

Note that this update only fixes the "Unauthorized Playback Device" error on standard-def content. HD content is still going to be just as picky about playback devices as it was before. Quicktime 7.5.7 is available now from Software Upate.