session values get updated

[eluser]yogesh_CI[/eluser]
Thanks for replay

This works but after some time(2 or 5 min) session values get updated again.

Is any other setting need to be change.

These are my settings in config.php

$config['sess_cookie_name'] = 'ci_session_CI';
$config['sess_expiration'] = 7200;
$config['sess_encrypt_cookie'] = FALSE;
$config['sess_use_database'] = FALSE;
$config['sess_table_name'] = 'ci_sessions_CI';
$config['sess_match_ip'] = FALSE;
$config['sess_match_useragent'] = TRUE;
$config['sess_time_to_update'] = 300;

Thanks again.