I am running FCP 4.5 on Mac OS 10.3.9. Using QT 7.4 So it goes without saying I use Quicktime files all the time. I export from FCP to QT .mov all the time. But what I don't understand is why I frequently have trouble importing a Quicktime file into FCP 4.5. Often its a file someone else sends me. I've tried both the official 'import' function and drag and drop... If I do drag and drop, I get an error saying, "File error: Unknown file." If I try import / file I get an error saying, "File error: 1 file(s) recognized, 0 access denied, 1 unknown." Is the frame rate a problem? The file 'movie properties' says video is H.264 Sometimes I will convert the file to another format and then I can import it fine into QT. But this doesn't make sense to me. What gives?