The standard way of altering form elements and setting them disabled does not work with cck fields.
<?php
function my_module_form_alter(&$form, &$form_state, $form_id) {
$form['my_element']['#disabled'] = true;
}
?>
The FAPI process handler of the CCK field won't transfer the #disabled attribute to its children elements.
You'll need this snippet to make it work.
<?php
/**?>
