iMovie for iOS: Some video clips do not appear in the Video browser
iMovie for iOS
After importing or transferring video clips from an external camera to your iPad 2 or later, iPhone 4 or later, or iPod touch (4th generation), the video clips may not appear in the Video browser within iMovie.
To resolve this issue, upgrade to iOS 5 or later and iMovie for iOS 1.2.2 or later. iMovie for iOS 1.2.2 includes expanded support for videos imported from external cameras.