Help with an unexpected error [SOLVED]

I recently created some hub pages which work fine. but since whenever i go gto log in i get this error.

Warning: Cannot modify header information - headers already sent by (output started at /home/atlasvi1/public_html/core/modules/eddf/eddf.php:2) in /home/atlasvi1/public_html/core/modules/Login/Login.php on line 154

if i go to log in again i get the " error you are already logged in" and can proceed as normal.

my eddf.php is very simple just shows

<?php
class eddf extends CodonModule
{

       public function index()
       {    
       Template::Show('eddf_hub.tpl');
       }
}

?>

the login.php line 154 is this

header('Location: '.url('/'.$this->post->redir));

any ideas?

It is a white space error. Look at all your modified php core files and see if there is any white space before the opening php tag or after the closing tag. Make sure you try to clear any space after the closing tag, even if it looks like it is the last line.

The error showing on line 154 is just where it catches up with it, it is somewhere before that in that file or a file called prior to that.

Thats got it, thanks Dave, blank line at the top was the culprit.

Cheers