Sounds like a gphoto problem to me. Which version (`ghoto2 -v`) do you use? What does `gphoto2 --list-cameras` show? What does `gphoto2 --list-files` show? Does `gphoto2 --get-file=NR` (NR= number for the AVI file) work? (Alternatively: `gphoto2 --get-all-files`)