Use of CCK and custom validation

Hello,

Sorry if this is a Drupal/CCK and not Translation Management issue.

I created a custom type using CCK and trying to add some basic validation logic to icl_translate_editor form.
I used this code to accomplish this:

function MyModule_form_icl_translate_editor_alter(&$form, &$form_state)   {
      $form['#validate'] = array('icl_translate_editor_validate');
}
function icl_translate_editor_validate(&$form, &$form_state)    {
     ... validating the filelds ...
     if( $error )     {
	    form_set_error('field', t('error message'));
	}
}

But this problem is that if validation fails after submitting the form and function form_set_error is called, the next page display the same form and SOME of CCK fields become empty.
Do i miss something? Why some of the fields are filled and some not?

Thank you!