error code 1096?

[eluser]tnathos[/eluser]
mmm i dont know for what show me this error if the select works fine..

Code:

function getPreguntas()
    {    
        $this->db->select('idPregunta');
        $this->db->from('jgo_asignadas_prefree');
        $this->db->where('estado','PD');
        $this->db->where('id',$this->session->userdata('id'));
        $query = $this->db->get();    
        if($query->num_rows() > 0){        
            return $this->db->get();
        }
    }

the curious is if quit $query = $this->db->get(); and the (if) and only put return $this->db->get();, yes works... any?