Core vs Reactor uri_string

[eluser]osci[/eluser]
Vanilla installations from bitbucket

same configs for both core and reactor

Code:

$config['base_url']    = 'http://ci.gr.local/';
$config['index_page'] = '';

URL to test

Code:

http://ci.gr.local/welcome

Code:

//Core returns
$URI->uri_string == '/welcome'
//Reactor returns
$URI->uri_string == 'welcome'

PS :in core version in system/core/URI.php at end of set_uri_string()

Code:

if ($parsed_uri != '')
{
   $parsed_uri = '/'.$parsed_uri;
}
return $parsed_uri;

Shouldn't both frameworks return the same?