Default image path

Hi,
I have updated my Drupal from 4.5 to 4.7.2
Now I also need to update the image module.
I have executed "update-image.php" script but it has a problem:
I must set the "default image path", a subdirectory in "files" directory.
So I move my old image dir (/gallerie) from "immagini" directory in "files" directory.
The actual situation is: /files/gallerie with permissions set on 775.
When I choose the "Default image path" as "/gallerie" or "gallerie", I obtain this problem:

"the directory doesn't exist"

Why???

Thanks,
Michele