flexi auth - A user authentication library for CodeIgniter

[eluser]Klausch[/eluser]
Hi,

I am very interested in this library, we have just begin our first greate CodeIgniter project with the need of a flexible and scalable user registration and adminsitration system.
I have installed the full demo version but until now it fails running correctly.
Opening the demosite on my local machine, using the URL:
http://adsite.localhost (this is the development domain of our project)
the homepage shows but in the upper part of the screen the following error is shown:

A PHP Error was encountered
Severity: Notice
Message: Undefined index: custom
Filename: models/flexi_auth_lite_model.php
Line Number: 86

And this particular line looks like:
$this->auth->tbl_custom_data = $this->auth->auth_database['custom'];

Also I notice some strange thingd in the DB script:
-Some fields labeled _fk but no actual FK constraints are defined
-Some Primary Key fields are also defined as UNIQUE which is redundant IMHO

I willpost more details as I encounter them, I see that the code is very new and I am willing to use it, but we must get on track pretty soon, or my boss will demand for falling back to Ion Auth...
Any suggestions are welcome