Trouble with old quicktime movie files

I get this error message:

The file could not be imported: The file “Macintosh HD/Users/kpetty/Pictures/iPhoto Library/Originals/2005/Egypt/Sharm El Sheik_2.mov” can’t be imported; QuickTime couldn’t parse it: -2048

The same error message pops up when I've tried to play them with Quicktime player, import them to iMovie, etc. There doesn't seem to be any rhyme or reason why some of the files work and some don't. They all have the same file extension, were shot with the same camera around the same time. Any guidance would be appreciated.