Documentation for private store support

What did you put in both pathfiles ?
For me (windows 2000) it works perfectly with
Public file system path: files
Private file system path: files/drupal_private

I add some troubles at the begining because I put some absolute path, and in fact it works like a charm with relative paths. Note : private file system path as to be included inside public system path.
Then it's up to you to prohibit apache browsing the content inside this private directory.

I think there should have a little more help here.

The documentation definitely needs to be updated to indicate that the private directory needs to be under the files directory. it would also be helpful to say what the ownership and permissions of the directory should be.

private path should not have to be under the public filepath. I'll look into any code that would cause that to be true.

The code that requires it is embedded deep into the includes/file.inc file. It does a check to see that the correct paths are within the drupal files path before moving or copying files.

I had run into this bug myself when I was starting to use private files.

Hmm... I thought I worked around that a long time ago. I have had to recreate the file_move, _copy and _transfer functions as private members which don't include the restriction to the base file directory. The next check to HEAD will resolve this after I finish testing.