Hi I have changed the:
header('Content-type: application/pdf');
to
header('Content-Type: application/octet-stream');
but still not working sadly for the (php coding way - still downloads a zero byte PDF)
the AddType application/octet-stream did however work for the htaccess way as I said above (just not on IE)
the clearing cache thing also didnt work.
thanks for the suggestions though.