Since 33 RPM relies heavily on QuickTime technology, it unfortunately shares several quirks that are also found with the QuickTime Player.
Protected video content downloaded from the iTunes Store (.m4v files) will display a gray screen. You will need to use either iTunes or the QuickTime Player to view these files.
If a song is paused, but the speed is changed, the song will begin playing again.
QuickTime MPG Movies
When the speed of an MPG movie is changed, the pitch will also change. This issue only affects MPG movies.