Problem with serialization of data

[eluser]vikascoollives[/eluser]
Here is my config.php code for session

$config['sess_cookie_name'] = 'ci_session';
$config['sess_expiration'] = 0;
$config['sess_encrypt_cookie'] = FALSE;
$config['sess_use_database'] = TRUE;
$config['sess_table_name'] = 'my_sessions';
$config['sess_match_ip'] = FALSE;
$config['sess_match_useragent'] = TRUE;
$config['sess_time_to_update'] = 300;