Just off-hand, if the file is an mpg as you suggested & QT can't open it, it sounds as though it might be corrupted. Either that or it was encoded in such a way (possibly on a pc) that is not fully supported by the version of QT you have. Do you have the standard or Pro version of QT? I'm not sure about all the ins & outs of QT & the playing diff b/w standard & pro, but there might be an xtra QT codec you need. Pro allows more options. Just a thought. Large QT files don't always transport very well.