Php pošiljanje priponk na mail

Imam spodnjo kodo, ki mi pošilja priponko na email. Deluje ok, ko prožim skripto jaz, če pa isto skripto nastavim na cron pa mi pošlje mail brez priponke.
Kaj bi lahko bilo narobe?
Mogoče je kje kaka napaka?

$uid = md5(uniqid(time()));
$header = "From: xxx@xxx.xx>\r\n";
$header .= "MIME-Version: 1.0\r\n";
$header .= "Content-Type: multipart/mixed; boundary=\"".$uid."\"\r\n\r\n";
$filename = "test.pdf";
$subject = "test subject";
$message = "testno prvo sporocilo";
$content = file_get_contents($filename);
$content = chunk_split(base64_encode($content));

// message & attachment
$nmessage = "--".$uid."\r\n";
$nmessage .= "Content-type:text/plain; charset=iso-8859-1\r\n";
$nmessage .= "Content-Transfer-Encoding: 7bit\r\n\r\n";
$nmessage .= $message."\r\n\r\n";
$nmessage .= "--".$uid."\r\n";
$nmessage .= "Content-Type: application/octet-stream; name=\"".$filename."\"\r\n";
$nmessage .= "Content-Transfer-Encoding: base64\r\n";
$nmessage .= "Content-Disposition: attachment; filename=\"".$filename."\"\r\n\r\n";
$nmessage .= $content."\r\n\r\n";
$nmessage .= "--".$uid."--";

mail("xxx@xxx.xx", $subject, $nmessage, $header);

Hvala, sem spremenil in dela :)
Edino ime datoteke da kot celi link. Lahko spremenim ime datoteke po pripetju?

Sem zrihtal. Hvala za nasvete.