I recently purchased a MacBook Air and transferred all my iTunes and iPhoto files from my external HD. All my iTunes files play fine on the Air. However, every time I double-click a picture to expand it, a "!" comes up. I've rebuilt the library and used 3rd party apps to rebuild and fix as well....still no luck. My Mac Pro's library(the original location of the iPhoto library) has absolutely no problems displaying them. I've done this process of copying these files on all my previous MacBook and MacBook Pro purchases. Any help is appreciated.