I added some custom fields to user profile and override the user profile edit form with my own template: user-profile-form.tpl.php. In this template I render the form out as below:

 unset($form['account']);
                         unset($form['mimemail']); 
			 unset($form['contact']);		
			 print drupal_render_children($form); 

And then display the user profile in user-profile.tpl.php as follows:
print render($user_profile['field_romanname']);
print render($user_profile['field_chinesename']);
............................

It had no problem when I set up the side as single language (English), I could render the form and saved the user profile fields with language to be 'und'. However, when I added another language to the site and translated these user profile fields (the labels only) into Chinese, I could not save the fields in Chinese. The form automatically renders the fields in English only. I want to save the fields in 'und' language and display them even when I change the language to Chinese. How can I do that? Thanks.