Active Record Inserting 0

[eluser]Firstrow[/eluser]
Hello all,
I have a problem with Active Record inserting.

Code in controller:

Code:

function insert()
    {
        $data = array(
        'title' => $this->input->post('title'),
        'keywords' => $this->input->post('keywords'),
        etc...
        );

        $this->model_name->insert($data);
    }

Code in Model:

Code:

function insert($data)
    {
        $this->db->insert('settings',$data);
    }

sql:

Code:

`title` varchar(255) NOT NULL,
`keywords` varchar(255) NOT NULL,

Here is my problem:
if title or keywords in $data array are empty its inserting 0
but i need to insert real empty string not 0.

Can somebody help me?