I searched for a while for this issue.
If you want to remove the click you have to define it in your field list for each column with remove_onclick = true
$this->fields_list = array(
'id_category' => array(
'title' => $this->l('Id'),
'width' => 140,
'type' => 'text',
),
'name' => array(
'title' => $this->l('Name'),
'width' => 140,
'type' => 'text',
'remove_onclick' => true
),
);