Paypal IPN keeps Retrying, but notification url did't even got callback

Question

I've done test everying in Paypal sandbox, and everything goes well.
Then I'm trying to go live, but it is very strange that all my payment notification
just keeps retrying. And there is even no response (or response code) from my site.
I even try to commet all my php script and write:

<?php
writeFile("debug.log","up\n",'a');
function writeFile($file, $str, $mode = 'w')
{
    $oldmask = @umask(0);
    $fp      = @fopen($file, $mode);
    @flock($fp, 3);
    if (!$fp) {
        Return false;
    } else {
        @fwrite($fp, $str);
        @fclose($fp);
        @umask($oldmask);
        Return true;
    }
}
?>

And guess what? nothing.
no logs written.
the script didn't event fire up.
but i call my url manually, i got my log.
it just keeps retrying, and i got nothing.
so, seems like, the IPN did't even call that url.
my web is hosted on godaddy.
please help me in here, many thanks!

here are ipn infomations:

Message ID                             7XL84004V1546282C
Date/time created                      2/13/2014 00:44 PST
Original/Resent                        Original
Latest delivery attempt date/time      2/13/2014 01:26 PST
Notification URL                       [hidden manually]
HTTP response code
What's this?
Delivery status                        Retrying
No. of retries                         9

as you can see, there is nothing in the row "HTTP response code".

Answer 1

ok I know what is going on here.
ALWAYS REMEMBER TO ADD http:// or https:// to Paypal button for your IPN listener url!
mine was like
<input type="hidden" name="notify_url" value="www.blahblah.com/test/paypal_ipn.php">
this fails, but

<input type="hidden" name="notify_url" value="http://www.blahblah.com/test/paypal_ipn.php">
works fine :)