can anybody explain why submitted php files treated with a server like a text file ?

The symptom happens when i attempt to gain access to a php file, the server send me this content from the file.

i've edited and set a part of content as requested. This really is output i see within the browser

*** WHAT : Removinng Meta Box in Publish using $pageshow factor WHY :*****************************************/function bk_cdp_meta_box($pageshow) situation 'postnew.php' : add_action('dbx_publish_advanced', 'bk_cdp_meta_box_reindex') break situation 'pagenew.php' : add_action('page_advanced', 'bk_cdp_meta_box_reindex') break default : if ($pageshow != "") /**************************************** WHAT : Reindex List all Publish panel Metaboxes before get remove or give a new meta_box WHY : FIXME : TODO : RETURN : ARGs :***

i download things i have upload and all of them has <?php when i code it before, therefore the supply of problem exist elsewhere.

In case your code sample is from the beginning of the file the issue is you do not have any opening PHP tags e.g. <?php

you're missing the php open tags and also the comment tags are wrong. Do this:

    <?php
    function bk_cdp_meta_box($pageshow) { 
           switch ($pageshow) { 
              case 'postnew.php' : 
              add_action('dbx_post_advanced', 'bk_cdp_meta_box_reindex'); 
              break; 

              case 'pagenew.php' : 
              add_action('page_advanced', 'bk_cdp_meta_box_reindex'); 
              break; 

              default : 
           } 
       if ($pageshow != "") {
      // remove_meta_box('postcustom', 'post', 'normal');
      // remove_meta_box('postexcerpt', 'post', 'normal');
      // remove_meta_box('trackbacks', 'post', 'normal'); 
     }
}

?>

This may happen in case your new submitted files does not get executable attribute and also the server is set up to avoid execution of these files. I have never witnessed this type of factor though.