Thanks for replying. When I selected File|Open File menu option, Quicktime didn't include m4v files as Movies in the file dialog, so I thought that it didn't play m4v files. I went back to Quicktime and changed the file dialog to All File Types, and then it does see m4v files as Quicktime Movies. I haven't tried yet to play the file.
Re: Attack of the Phantom, does anyone know where to get the m4v version? The one torrent I found isn't seeded anymore.