I have a strange problem with my project.
I edited on a mac pro with FCP a clip for a customer. Independent audio tracks were recorded in wav format with a Zoom H4N and put in the timeline. After I finished the editing I made a backup of all the files and folders containing the footage and projects on an external hard disk. When I open the project from the external hd on my macbook pro everything looks fine exept the audio of the wavs files are completely white and empty (no waveform, no sound). If I do a reconnect media with the original files copied on the back up hd the audio gets completely out of sync. If instead I do a match frame, FCP founds the perfect sync on the original footage in the bin. What is the cause?