Cant fill session inside class

Hi there, I have little problem. I have class named listing - for product listing and I have few sections. I want to reset filter when Im in another section. I made it this way, but its not working.. I cant fill $_SESSION['sekc'] with actual value... Can anybody tell me why? Thanks...

class listing
{	
	function __construct($section)
	{
		$this->section = clean_text($section);	
		
		echo 'old - ' . $_SESSION['sekc'] . '<br />'; //Print old sekc - never changes
		echo 'new - ' . $this->section . '<br />';	//Print new section
		
		if ($_SESSION['sekc'] != $this->section)
		{
                       //some unsets....
		}
		unset($_SESSION['sekc']);
		echo $this->section; //Print correct value, the new section
		$_SESSION['sekc'] = $this->section;
		echo $_SESSION['sekc']; //Print correct value, the new section, but on another page reload I see the old value at top of the script. (ie: If i came from index, on top I see index and here I see the new value.)
	}
}

PHP:

Class calling:

$listing = new listing('index');

PHP:

and in another scripts Im changing the value (index).

 

add session_start()

 

Its there and server is using session.autostart.

EDIT: Hmm, bug is somewhere in the script, but not in these few lines... If I use them alone, all is ok, but in website nope...

 

Ouch, FAIL... I was calling this class in index.php and I had "ErrorDocument 404 /" in my htaccess. So when the error 404 was called, it calls index and it overwrites session....