Theme is breaking WordPress admin

I just installed a theme for a web site, and the theme works right on the pages, just a few tweaks need to be done. The problem is with the admin section. You can see what I mean when I go to the admin section, URL: The error is:

Warning: Cannot modify header information - headers already sent by (output started at /home/wwwoutdo/public_html/dev/wp-content/themes/wordpress-brown/functions.php:12) in /home/wwwoutdo/public_html/dev/wp-includes/pluggable.php on line 934

This is what functions.php looks like:

if ( function_exists('register_sidebar') )
    register_sidebars(2, array(
        'before_widget' => '<ul class="category-bg widget %2$s">',
        'after_widget' => '</ul>',
        'before_title' => '<h2>',
        'after_title' => '</h2>',

In pluggable.php, which is a WordPress file, I’ve found where it is calling the header() function. I have tried doing a fresh WordPress installation and reinstalling the theme but I get the same thing.

I don’t see any .php file relating to the admin part in the theme’s files, so I don’t know how it’s causing an error.

The default twenty eleven theme for WordPress works just fine as well, only this theme is causing problems.

I figured it out, it was simple. After the closing ‘?>’ tag in functions.php was some blank space. Delete/close thread please!