new session id on each page load

Every time I load/refresh a page CI generates a new session.

Code:

$config['sess_driver'] = 'database';
$config['sess_cookie_name'] = 'CIsession';
$config['sess_expiration'] = 7200;
$config['sess_save_path'] = 'sessions';
$config['sess_match_ip'] = FALSE;
$config['sess_time_to_update'] = 7200;
$config['sess_regenerate_destroy'] = FALSE;

I call session library in autoload

Code:

$autoload['libraries'] = array('session');

I have a coockiedomain set correctly

Code:

$config['cookie_domain']    = ".mydomain.com";

It stores the data in my database correctly, but on every page-load generates a new session. There are no errors in Apache nor in CI log. Do you have any ideas where to start? Thank you