Error on Including Controller

[eluser]Paulodemoc[/eluser]
Hello guys, I am having a different problem this time. I downloaded ION AUTH files and copied the config, library, language and model to my application. But i havent loaded any of these to my controllers. They are just laying there.
But now, everytime I try to access any controller I get a blank screen with the 500 Internal Server Error on the Firebug debug tool.
I tried to find the source of the error, putting some echoes, to see how far the application goes. I found out that the error happens on the line:

Code:

include_once(APPPATH.'controllers/'.$RTR->fetch_directory().$RTR->fetch_class().EXT);

I user var_dump on the include path and got the correct path to the controller. I tried to remove everything from the controller and left only:

Code:

<?php


class Validation extends Controller {


}
?>

And the include worked fine, now what I got was a message from CI saying 404 Page Not Found.

Any ideas what might be wrong with my controller? I am attaching it here.
I tried remove each function to see what I get, and still blank pages...

I am running out of ideas here... =/

[eluser]Paulodemoc[/eluser]
Solved. I rolled back to an older version. Funny thing is the only difference between the two is that I replaced all $_POST['....'] with $this->input->post('....').