What I am saying is try password protecting a single category.
To password protect an album you simply need the url and password
Its an automated thing.
Password Required - PhotoPost Photo Gallery
You get a url like that with a password on the end.
Code:
Content visible to verified customers only.
Notice you cant see that album without adding that on the end. The one main difference in password protection between an album or category is in a category the admin can set the password to what he likes. In personal albums its all done for users automatically.