trim|valid_email not working in validation

First I copy some input variables from a submitted form:

PHP Code:

$this->data['item']['xname'] = $this->input->post('xname');
$this->data['item']['xemail'] = $this->input->post('xemail'); 


Then I set the validation rules

PHP Code:

$this->form_validation->set_rules('xname','','trim|required');
$this->form_validation->set_rules('xemail','','trim|valid_email'); 


Then I set what to validate:

PHP Code:

$this->form_validation->set_data($this->data['item']); 


Then I validate

PHP Code:

if($this->form_validation->run()) 


No trim is done on $this->data['item'].