How to keep flash data in Codeigniter?

[eluser]Sein Kraft[/eluser]
I've a controller with a method there it catch an argument and set it in a flash var.

The question is...if i send many arguments to this method, using multiple firefox tabs but the same user session, could them get mixed or rewrited?

I mean, if i open a tab and send the "x" argument and is saved in a flash var and in another tab i send the argument "y" and is "x" rewrited by "y" or is handled like two different things? (i'm using stored sessions)

Also i'm having troubles keeping flash data. It don't keep for next use if i change between sections. If i go to modify/general the flashdata is deleted (replaced by 0).

My code:

Code:

function modify(){
    $section = $this->uri->segment(3);

    switch ($section) {
        case 'identity':
                $this->session->keep_flashdata('item');
                $this->_modify_identity();
            break;
        case 'general':
                $this->session->keep_flashdata('item');
                $this->_modify_general();
            break;
        case 'print':
                echo $this->session->flashdata('item');
            break;
        default:
                if(is_numeric($section)){
                    $this->session->set_flashdata('item', $section);
                }
                redirect('profile/modify/identity');
            break;
    }
}