insert in to TIMESTAMP field using ActiveRecords

[eluser]ningoo[/eluser]
I am trying to insert record in to profile table (see below) which has a column called 'lastlogin'.

The problem : CI inserts '0000-00-00 00:00:00' when i try to insert new record using active records.

my apologies , if i'm missing something thats obvious.

btw , thanks in advance

here's code

Code:

$profile_data = array(
              'member_id' => $member_id ,
              'membername' => $membername ,
              'profiledescription' => '' ,
              'lastlogin' => now(),
              'status' => 1,
                );
        
        $MAINDB->insert('profiles', $profile_data);

and heres table schema

Code:

create table `profiles` (
    `id` double ,
    `member_id` double ,
    `membername` varchar (96),
    `profiledescription` blob ,
    `created` timestamp ,
    `lastlogin` timestamp ,
    `status` double
);