Hi,
I think there is a bug or at least a strange behaviour with the authentication form.
If you try to access to an authenticated URL with a full path or page, you are not redirected to this URL after the authentication.
Eg:
You define a restricted access on http://www.domain.com/auth/ but if you first try to go to http://www.domain.com/auth/folder/index.html you will be redirected to http://www.domain.com/auth/ after the authentication.
It could be better to be redirected to the URL you have entered after the authentication.
Bastien.